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[PATCH v7 1/9] PCI: Allow per function PCI slots

by Farhan Ali

On s390 systems, which use a machine level hypervisor, PCI devices are always accessed through a form of PCI pass-through which fundamentally operates on a per PCI function granularity. This is also reflected in the s390 PCI hotplug driver which creates hotplug slots for individual PCI functions. Its reset_slot() function, which is a wrapper for zpci_hot_reset_device(), thus also resets individual functions. Currently, the kernel's PCI_SLOT() macro assigns the same pci_slot object to multifunction devices. This approach worked fine on s390 systems that only exposed virtual functions as individual PCI domains to the operating system. Since commit 44510d6fa0c0 ("s390/pci: Handling multifunctions") s390 supports exposing the topology of multifunction PCI devices by grouping them in a shared PCI domain. When attempting to reset a function through the hotplug driver, the shared slot assignment causes the wrong function to be reset instead of the intended one. It also leaks memory as we do create a pci_slot object for the function, but don't correctly free it in pci_slot_release(). Add a flag for struct pci_slot to allow per function PCI slots for functions managed through a hypervisor, which exposes individual PCI functions while retaining the topology. Fixes: 44510d6fa0c0 ("s390/pci: Handling multifunctions") Cc: stable(a)vger.kernel.org Suggested-by: Niklas Schnelle <schnelle(a)linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle(a)linux.ibm.com> Signed-off-by: Farhan Ali <alifm(a)linux.ibm.com> --- drivers/pci/pci.c | 5 +++-- drivers/pci/slot.c | 25 ++++++++++++++++++++++--- include/linux/pci.h | 1 + 3 files changed, 26 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 13dbb405dc31..c105e285cff8 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4832,8 +4832,9 @@ static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, bool probe) static int pci_dev_reset_slot_function(struct pci_dev *dev, bool probe) { - if (dev->multifunction || dev->subordinate || !dev->slot || - dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET) + if (dev->subordinate || !dev->slot || + dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET || + (dev->multifunction && !dev->slot->per_func_slot)) return -ENOTTY; return pci_reset_hotplug_slot(dev->slot->hotplug, probe); diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c index 50fb3eb595fe..ed10fa3ae727 100644 --- a/drivers/pci/slot.c +++ b/drivers/pci/slot.c @@ -63,6 +63,22 @@ static ssize_t cur_speed_read_file(struct pci_slot *slot, char *buf) return bus_speed_read(slot->bus->cur_bus_speed, buf); } +static bool pci_dev_matches_slot(struct pci_dev *dev, struct pci_slot *slot) +{ + if (slot->per_func_slot) + return dev->devfn == slot->number; + + return PCI_SLOT(dev->devfn) == slot->number; +} + +static bool pci_slot_enabled_per_func(void) +{ + if (IS_ENABLED(CONFIG_S390)) + return true; + + return false; +} + static void pci_slot_release(struct kobject *kobj) { struct pci_dev *dev; @@ -73,7 +89,7 @@ static void pci_slot_release(struct kobject *kobj) down_read(&pci_bus_sem); list_for_each_entry(dev, &slot->bus->devices, bus_list) - if (PCI_SLOT(dev->devfn) == slot->number) + if (pci_dev_matches_slot(dev, slot)) dev->slot = NULL; up_read(&pci_bus_sem); @@ -166,7 +182,7 @@ void pci_dev_assign_slot(struct pci_dev *dev) mutex_lock(&pci_slot_mutex); list_for_each_entry(slot, &dev->bus->slots, list) - if (PCI_SLOT(dev->devfn) == slot->number) + if (pci_dev_matches_slot(dev, slot)) dev->slot = slot; mutex_unlock(&pci_slot_mutex); } @@ -265,6 +281,9 @@ struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr, slot->bus = pci_bus_get(parent); slot->number = slot_nr; + if (pci_slot_enabled_per_func()) + slot->per_func_slot = 1; + slot->kobj.kset = pci_slots_kset; slot_name = make_slot_name(name); @@ -285,7 +304,7 @@ struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr, down_read(&pci_bus_sem); list_for_each_entry(dev, &parent->devices, bus_list) - if (PCI_SLOT(dev->devfn) == slot_nr) + if (pci_dev_matches_slot(dev, slot)) dev->slot = slot; up_read(&pci_bus_sem); diff --git a/include/linux/pci.h b/include/linux/pci.h index 864775651c6f..08fa57beb7b2 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -78,6 +78,7 @@ struct pci_slot { struct list_head list; /* Node in list of slots */ struct hotplug_slot *hotplug; /* Hotplug info (move here) */ unsigned char number; /* PCI_SLOT(pci_dev->devfn) */ + unsigned int per_func_slot:1; /* Allow per function slot */ struct kobject kobj; }; -- 2.43.0

2 days, 7 hours

[PATCH] drm/vmwgfx: Fix an error return check in vmw_compat_shader_add()

by Haoxiang Li

In vmw_compat_shader_add(), the return value check of vmw_shader_alloc() is not proper. Modify the check for the return pointer 'res'. Found by code review and compiled on ubuntu 20.04. Fixes: 18e4a4669c50 ("drm/vmwgfx: Fix compat shader namespace") Cc: stable(a)vger.kernel.org Signed-off-by: Haoxiang Li <lihaoxiang(a)isrc.iscas.ac.cn> --- drivers/gpu/drm/vmwgfx/vmwgfx_shader.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c b/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c index 69dfe69ce0f8..7ed938710342 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c @@ -923,8 +923,10 @@ int vmw_compat_shader_add(struct vmw_private *dev_priv, ttm_bo_unreserve(&buf->tbo); res = vmw_shader_alloc(dev_priv, buf, size, 0, shader_type); - if (unlikely(ret != 0)) + if (IS_ERR(res)) { + ret = PTR_ERR(res); goto no_reserve; + } ret = vmw_cmdbuf_res_add(man, vmw_cmdbuf_res_shader, vmw_shader_key(user_key, shader_type), -- 2.25.1

2 days, 7 hours

[PATCH] rust: task: restrict Task::group_leader() to current

by Alice Ryhl

The Task::group_leader() method currently allows you to access the group_leader() of any task, for example one you hold a refcount to. But this is not safe in general since the group leader could change when a task exits. See for example commit a15f37a40145c ("kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths"). All existing users of Task::group_leader() call this method on current, which is guaranteed running, so there's not an actual issue in Rust code today. But to prevent code in the future from making this mistake, restrict Task::group_leader() so that it can only be called on current. There are some other cases where accessing task->group_leader is okay. For example it can be safe if you hold tasklist_lock or rcu_read_lock(). However, only supporting current->group_leader is sufficient for all in-tree Rust users of group_leader right now. Safe Rust functionality for accessing it under rcu or while holding tasklist_lock may be added in the future if required by any future Rust module. Reported-by: Oleg Nesterov <oleg(a)redhat.com> Closes: https://lore.kernel.org/all/aTLnV-5jlgfk1aRK@redhat.com/ Fixes: 313c4281bc9d ("rust: add basic `Task`") Cc: stable(a)vger.kernel.org Signed-off-by: Alice Ryhl <aliceryhl(a)google.com> --- The rust/kernel/task.rs file has had changes land through a few different trees: * Originally task.rs landed through Christian's tree together with file.rs and pid_namespace.rs * The change to add CurrentTask landed through Andrew Morton's tree together with mm.rs * There was a patch to mark some methods #[inline] that landed through tip via Boqun. I don't think there's a clear owner for this file, so to break ambiguity I'm doing to declare that this patch is intended for Andrew Morton's tree. Please let me know if you think a different tree is appropriate. --- rust/kernel/task.rs | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/rust/kernel/task.rs b/rust/kernel/task.rs index 49fad6de06740a9b9ad80b2f4b430cc28cd134fa..9440692a3a6d0d3f908d61d51dcd377a272f6957 100644 --- a/rust/kernel/task.rs +++ b/rust/kernel/task.rs @@ -204,18 +204,6 @@ pub fn as_ptr(&self) -> *mut bindings::task_struct { self.0.get() } - /// Returns the group leader of the given task. - pub fn group_leader(&self) -> &Task { - // SAFETY: The group leader of a task never changes after initialization, so reading this - // field is not a data race. - let ptr = unsafe { *ptr::addr_of!((*self.as_ptr()).group_leader) }; - - // SAFETY: The lifetime of the returned task reference is tied to the lifetime of `self`, - // and given that a task has a reference to its group leader, we know it must be valid for - // the lifetime of the returned task reference. - unsafe { &*ptr.cast() } - } - /// Returns the PID of the given task. pub fn pid(&self) -> Pid { // SAFETY: The pid of a task never changes after initialization, so reading this field is @@ -345,6 +333,18 @@ pub fn active_pid_ns(&self) -> Option<&PidNamespace> { // `release_task()` call. Some(unsafe { PidNamespace::from_ptr(active_ns) }) } + + /// Returns the group leader of the current task. + pub fn group_leader(&self) -> &Task { + // SAFETY: The group leader of a task never changes while the task is running, and `self` + // is the current task, which is guaranteed running. + let ptr = unsafe { (*self.as_ptr()).group_leader }; + + // SAFETY: `current.group_leader` stays valid for at least the duration in which `current` + // is running, and the signature of this function ensures that the returned `&Task` can + // only be used while `current` is still valid, thus still running. + unsafe { &*ptr.cast() } + } } // SAFETY: The type invariants guarantee that `Task` is always refcounted. --- base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8 change-id: 20251218-task-group-leader-a71931ced643 Best regards, -- Alice Ryhl <aliceryhl(a)google.com>

2 days, 8 hours

[PATCH 5.15] net: Remove RTNL dance for SIOCBRADDIF and SIOCBRDELIF.

by Thadeu Lima de Souza Cascardo

commit ed3ba9b6e280e14cc3148c1b226ba453f02fa76c upstream. SIOCBRDELIF is passed to dev_ioctl() first and later forwarded to br_ioctl_call(), which causes unnecessary RTNL dance and the splat below [0] under RTNL pressure. Let's say Thread A is trying to detach a device from a bridge and Thread B is trying to remove the bridge. In dev_ioctl(), Thread A bumps the bridge device's refcnt by netdev_hold() and releases RTNL because the following br_ioctl_call() also re-acquires RTNL. In the race window, Thread B could acquire RTNL and try to remove the bridge device. Then, rtnl_unlock() by Thread B will release RTNL and wait for netdev_put() by Thread A. Thread A, however, must hold RTNL after the unlock in dev_ifsioc(), which may take long under RTNL pressure, resulting in the splat by Thread B. Thread A (SIOCBRDELIF) Thread B (SIOCBRDELBR) ---------------------- ---------------------- sock_ioctl sock_ioctl `- sock_do_ioctl `- br_ioctl_call `- dev_ioctl `- br_ioctl_stub |- rtnl_lock | |- dev_ifsioc ' ' |- dev = __dev_get_by_name(...) |- netdev_hold(dev, ...) . / |- rtnl_unlock ------. | | |- br_ioctl_call `---> |- rtnl_lock Race | | `- br_ioctl_stub |- br_del_bridge Window | | | |- dev = __dev_get_by_name(...) | | | May take long | `- br_dev_delete(dev, ...) | | | under RTNL pressure | `- unregister_netdevice_queue(dev, ...) | | | | `- rtnl_unlock \ | |- rtnl_lock <-' `- netdev_run_todo | |- ... `- netdev_run_todo | `- rtnl_unlock |- __rtnl_unlock | |- netdev_wait_allrefs_any |- netdev_put(dev, ...) <----------------' Wait refcnt decrement and log splat below To avoid blocking SIOCBRDELBR unnecessarily, let's not call dev_ioctl() for SIOCBRADDIF and SIOCBRDELIF. In the dev_ioctl() path, we do the following: 1. Copy struct ifreq by get_user_ifreq in sock_do_ioctl() 2. Check CAP_NET_ADMIN in dev_ioctl() 3. Call dev_load() in dev_ioctl() 4. Fetch the master dev from ifr.ifr_name in dev_ifsioc() 3. can be done by request_module() in br_ioctl_call(), so we move 1., 2., and 4. to br_ioctl_stub(). Note that 2. is also checked later in add_del_if(), but it's better performed before RTNL. SIOCBRADDIF and SIOCBRDELIF have been processed in dev_ioctl() since the pre-git era, and there seems to be no specific reason to process them there. [0]: unregister_netdevice: waiting for wpan3 to become free. Usage count = 2 ref_tracker: wpan3@ffff8880662d8608 has 1/1 users at __netdev_tracker_alloc include/linux/netdevice.h:4282 [inline] netdev_hold include/linux/netdevice.h:4311 [inline] dev_ifsioc+0xc6a/0x1160 net/core/dev_ioctl.c:624 dev_ioctl+0x255/0x10c0 net/core/dev_ioctl.c:826 sock_do_ioctl+0x1ca/0x260 net/socket.c:1213 sock_ioctl+0x23a/0x6c0 net/socket.c:1318 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x1a4/0x210 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcb/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 893b19587534 ("net: bridge: fix ioctl locking") Reported-by: syzkaller <syzkaller(a)googlegroups.com> Reported-by: yan kang <kangyan91(a)outlook.com> Reported-by: yue sun <samsun1006219(a)gmail.com> Closes: https://lore.kernel.org/netdev/SY8P300MB0421225D54EB92762AE8F0F2A1D32@SY8P3… Signed-off-by: Kuniyuki Iwashima <kuniyu(a)amazon.com> Acked-by: Stanislav Fomichev <sdf(a)fomichev.me> Reviewed-by: Ido Schimmel <idosch(a)nvidia.com> Acked-by: Nikolay Aleksandrov <razor(a)blackwall.org> Link: https://patch.msgid.link/20250316192851.19781-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni(a)redhat.com> [cascardo: fixed conflict at dev_ifsioc] Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo(a)igalia.com> --- include/linux/if_bridge.h | 6 ++---- net/bridge/br_ioctl.c | 36 +++++++++++++++++++++++++++++++++--- net/bridge/br_private.h | 3 +-- net/core/dev_ioctl.c | 15 --------------- net/socket.c | 19 +++++++++---------- 5 files changed, 45 insertions(+), 34 deletions(-) diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h index 509e18c7e740..37082feae336 100644 --- a/include/linux/if_bridge.h +++ b/include/linux/if_bridge.h @@ -62,11 +62,9 @@ struct br_ip_list { #define BR_DEFAULT_AGEING_TIME (300 * HZ) struct net_bridge; -void brioctl_set(int (*hook)(struct net *net, struct net_bridge *br, - unsigned int cmd, struct ifreq *ifr, +void brioctl_set(int (*hook)(struct net *net, unsigned int cmd, void __user *uarg)); -int br_ioctl_call(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg); +int br_ioctl_call(struct net *net, unsigned int cmd, void __user *uarg); #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING) int br_multicast_list_adjacent(struct net_device *dev, diff --git a/net/bridge/br_ioctl.c b/net/bridge/br_ioctl.c index 9922497e59f8..85c23a38bdb2 100644 --- a/net/bridge/br_ioctl.c +++ b/net/bridge/br_ioctl.c @@ -368,10 +368,26 @@ static int old_deviceless(struct net *net, void __user *uarg) return -EOPNOTSUPP; } -int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg) +int br_ioctl_stub(struct net *net, unsigned int cmd, void __user *uarg) { int ret = -EOPNOTSUPP; + struct ifreq ifr; + + if (cmd == SIOCBRADDIF || cmd == SIOCBRDELIF) { + void __user *data; + char *colon; + + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + if (get_user_ifreq(&ifr, &data, uarg)) + return -EFAULT; + + ifr.ifr_name[IFNAMSIZ - 1] = 0; + colon = strchr(ifr.ifr_name, ':'); + if (colon) + *colon = 0; + } rtnl_lock(); @@ -404,7 +420,21 @@ int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd, break; case SIOCBRADDIF: case SIOCBRDELIF: - ret = add_del_if(br, ifr->ifr_ifindex, cmd == SIOCBRADDIF); + { + struct net_device *dev; + + dev = __dev_get_by_name(net, ifr.ifr_name); + if (!dev || !netif_device_present(dev)) { + ret = -ENODEV; + break; + } + if (!netif_is_bridge_master(dev)) { + ret = -EOPNOTSUPP; + break; + } + + ret = add_del_if(netdev_priv(dev), ifr.ifr_ifindex, cmd == SIOCBRADDIF); + } break; } diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 8acb427ae6de..0cf756677953 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -874,8 +874,7 @@ br_port_get_check_rtnl(const struct net_device *dev) /* br_ioctl.c */ int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq, void __user *data, int cmd); -int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg); +int br_ioctl_stub(struct net *net, unsigned int cmd, void __user *uarg); /* br_multicast.c */ #ifdef CONFIG_BRIDGE_IGMP_SNOOPING diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c index 6ddfd7bfc512..30fca446f58a 100644 --- a/net/core/dev_ioctl.c +++ b/net/core/dev_ioctl.c @@ -375,19 +375,6 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data, case SIOCWANDEV: return dev_siocwandev(dev, &ifr->ifr_settings); - case SIOCBRADDIF: - case SIOCBRDELIF: - if (!netif_device_present(dev)) - return -ENODEV; - if (!netif_is_bridge_master(dev)) - return -EOPNOTSUPP; - dev_hold(dev); - rtnl_unlock(); - err = br_ioctl_call(net, netdev_priv(dev), cmd, ifr, NULL); - dev_put(dev); - rtnl_lock(); - return err; - case SIOCSHWTSTAMP: err = net_hwtstamp_validate(ifr); if (err) @@ -574,8 +561,6 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr, case SIOCBONDRELEASE: case SIOCBONDSETHWADDR: case SIOCBONDCHANGEACTIVE: - case SIOCBRADDIF: - case SIOCBRDELIF: case SIOCSHWTSTAMP: if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) return -EPERM; diff --git a/net/socket.c b/net/socket.c index 1d71fa44ace4..f3d0a8d66cce 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1097,12 +1097,10 @@ static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from) */ static DEFINE_MUTEX(br_ioctl_mutex); -static int (*br_ioctl_hook)(struct net *net, struct net_bridge *br, - unsigned int cmd, struct ifreq *ifr, +static int (*br_ioctl_hook)(struct net *net, unsigned int cmd, void __user *uarg); -void brioctl_set(int (*hook)(struct net *net, struct net_bridge *br, - unsigned int cmd, struct ifreq *ifr, +void brioctl_set(int (*hook)(struct net *net, unsigned int cmd, void __user *uarg)) { mutex_lock(&br_ioctl_mutex); @@ -1111,8 +1109,7 @@ void brioctl_set(int (*hook)(struct net *net, struct net_bridge *br, } EXPORT_SYMBOL(brioctl_set); -int br_ioctl_call(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg) +int br_ioctl_call(struct net *net, unsigned int cmd, void __user *uarg) { int err = -ENOPKG; @@ -1121,7 +1118,7 @@ int br_ioctl_call(struct net *net, struct net_bridge *br, unsigned int cmd, mutex_lock(&br_ioctl_mutex); if (br_ioctl_hook) - err = br_ioctl_hook(net, br, cmd, ifr, uarg); + err = br_ioctl_hook(net, cmd, uarg); mutex_unlock(&br_ioctl_mutex); return err; @@ -1218,7 +1215,9 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg) case SIOCSIFBR: case SIOCBRADDBR: case SIOCBRDELBR: - err = br_ioctl_call(net, NULL, cmd, NULL, argp); + case SIOCBRADDIF: + case SIOCBRDELIF: + err = br_ioctl_call(net, cmd, argp); break; case SIOCGIFVLAN: case SIOCSIFVLAN: @@ -3321,6 +3320,8 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock, case SIOCGPGRP: case SIOCBRADDBR: case SIOCBRDELBR: + case SIOCBRADDIF: + case SIOCBRDELIF: case SIOCGIFVLAN: case SIOCSIFVLAN: case SIOCGSKNS: @@ -3358,8 +3359,6 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock, case SIOCGIFPFLAGS: case SIOCGIFTXQLEN: case SIOCSIFTXQLEN: - case SIOCBRADDIF: - case SIOCBRDELIF: case SIOCGIFNAME: case SIOCSIFNAME: case SIOCGMIIPHY: -- 2.47.3

2 days, 8 hours

[PATCH 6.1] net: Remove RTNL dance for SIOCBRADDIF and SIOCBRDELIF.

by Thadeu Lima de Souza Cascardo

commit ed3ba9b6e280e14cc3148c1b226ba453f02fa76c upstream. SIOCBRDELIF is passed to dev_ioctl() first and later forwarded to br_ioctl_call(), which causes unnecessary RTNL dance and the splat below [0] under RTNL pressure. Let's say Thread A is trying to detach a device from a bridge and Thread B is trying to remove the bridge. In dev_ioctl(), Thread A bumps the bridge device's refcnt by netdev_hold() and releases RTNL because the following br_ioctl_call() also re-acquires RTNL. In the race window, Thread B could acquire RTNL and try to remove the bridge device. Then, rtnl_unlock() by Thread B will release RTNL and wait for netdev_put() by Thread A. Thread A, however, must hold RTNL after the unlock in dev_ifsioc(), which may take long under RTNL pressure, resulting in the splat by Thread B. Thread A (SIOCBRDELIF) Thread B (SIOCBRDELBR) ---------------------- ---------------------- sock_ioctl sock_ioctl `- sock_do_ioctl `- br_ioctl_call `- dev_ioctl `- br_ioctl_stub |- rtnl_lock | |- dev_ifsioc ' ' |- dev = __dev_get_by_name(...) |- netdev_hold(dev, ...) . / |- rtnl_unlock ------. | | |- br_ioctl_call `---> |- rtnl_lock Race | | `- br_ioctl_stub |- br_del_bridge Window | | | |- dev = __dev_get_by_name(...) | | | May take long | `- br_dev_delete(dev, ...) | | | under RTNL pressure | `- unregister_netdevice_queue(dev, ...) | | | | `- rtnl_unlock \ | |- rtnl_lock <-' `- netdev_run_todo | |- ... `- netdev_run_todo | `- rtnl_unlock |- __rtnl_unlock | |- netdev_wait_allrefs_any |- netdev_put(dev, ...) <----------------' Wait refcnt decrement and log splat below To avoid blocking SIOCBRDELBR unnecessarily, let's not call dev_ioctl() for SIOCBRADDIF and SIOCBRDELIF. In the dev_ioctl() path, we do the following: 1. Copy struct ifreq by get_user_ifreq in sock_do_ioctl() 2. Check CAP_NET_ADMIN in dev_ioctl() 3. Call dev_load() in dev_ioctl() 4. Fetch the master dev from ifr.ifr_name in dev_ifsioc() 3. can be done by request_module() in br_ioctl_call(), so we move 1., 2., and 4. to br_ioctl_stub(). Note that 2. is also checked later in add_del_if(), but it's better performed before RTNL. SIOCBRADDIF and SIOCBRDELIF have been processed in dev_ioctl() since the pre-git era, and there seems to be no specific reason to process them there. [0]: unregister_netdevice: waiting for wpan3 to become free. Usage count = 2 ref_tracker: wpan3@ffff8880662d8608 has 1/1 users at __netdev_tracker_alloc include/linux/netdevice.h:4282 [inline] netdev_hold include/linux/netdevice.h:4311 [inline] dev_ifsioc+0xc6a/0x1160 net/core/dev_ioctl.c:624 dev_ioctl+0x255/0x10c0 net/core/dev_ioctl.c:826 sock_do_ioctl+0x1ca/0x260 net/socket.c:1213 sock_ioctl+0x23a/0x6c0 net/socket.c:1318 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x1a4/0x210 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcb/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 893b19587534 ("net: bridge: fix ioctl locking") Reported-by: syzkaller <syzkaller(a)googlegroups.com> Reported-by: yan kang <kangyan91(a)outlook.com> Reported-by: yue sun <samsun1006219(a)gmail.com> Closes: https://lore.kernel.org/netdev/SY8P300MB0421225D54EB92762AE8F0F2A1D32@SY8P3… Signed-off-by: Kuniyuki Iwashima <kuniyu(a)amazon.com> Acked-by: Stanislav Fomichev <sdf(a)fomichev.me> Reviewed-by: Ido Schimmel <idosch(a)nvidia.com> Acked-by: Nikolay Aleksandrov <razor(a)blackwall.org> Link: https://patch.msgid.link/20250316192851.19781-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni(a)redhat.com> [cascardo: fixed conflict at dev_ifsioc] Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo(a)igalia.com> --- include/linux/if_bridge.h | 6 ++---- net/bridge/br_ioctl.c | 36 +++++++++++++++++++++++++++++++++--- net/bridge/br_private.h | 3 +-- net/core/dev_ioctl.c | 16 ---------------- net/socket.c | 19 +++++++++---------- 5 files changed, 45 insertions(+), 35 deletions(-) diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h index d62ef428e3aa..3963f0af4dad 100644 --- a/include/linux/if_bridge.h +++ b/include/linux/if_bridge.h @@ -63,11 +63,9 @@ struct br_ip_list { #define BR_DEFAULT_AGEING_TIME (300 * HZ) struct net_bridge; -void brioctl_set(int (*hook)(struct net *net, struct net_bridge *br, - unsigned int cmd, struct ifreq *ifr, +void brioctl_set(int (*hook)(struct net *net, unsigned int cmd, void __user *uarg)); -int br_ioctl_call(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg); +int br_ioctl_call(struct net *net, unsigned int cmd, void __user *uarg); #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING) int br_multicast_list_adjacent(struct net_device *dev, diff --git a/net/bridge/br_ioctl.c b/net/bridge/br_ioctl.c index f213ed108361..6bc0a11f2ed3 100644 --- a/net/bridge/br_ioctl.c +++ b/net/bridge/br_ioctl.c @@ -394,10 +394,26 @@ static int old_deviceless(struct net *net, void __user *data) return -EOPNOTSUPP; } -int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg) +int br_ioctl_stub(struct net *net, unsigned int cmd, void __user *uarg) { int ret = -EOPNOTSUPP; + struct ifreq ifr; + + if (cmd == SIOCBRADDIF || cmd == SIOCBRDELIF) { + void __user *data; + char *colon; + + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + if (get_user_ifreq(&ifr, &data, uarg)) + return -EFAULT; + + ifr.ifr_name[IFNAMSIZ - 1] = 0; + colon = strchr(ifr.ifr_name, ':'); + if (colon) + *colon = 0; + } rtnl_lock(); @@ -430,7 +446,21 @@ int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd, break; case SIOCBRADDIF: case SIOCBRDELIF: - ret = add_del_if(br, ifr->ifr_ifindex, cmd == SIOCBRADDIF); + { + struct net_device *dev; + + dev = __dev_get_by_name(net, ifr.ifr_name); + if (!dev || !netif_device_present(dev)) { + ret = -ENODEV; + break; + } + if (!netif_is_bridge_master(dev)) { + ret = -EOPNOTSUPP; + break; + } + + ret = add_del_if(netdev_priv(dev), ifr.ifr_ifindex, cmd == SIOCBRADDIF); + } break; } diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 901b9f609b0c..2d3859c2979a 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -894,8 +894,7 @@ br_port_get_check_rtnl(const struct net_device *dev) /* br_ioctl.c */ int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq, void __user *data, int cmd); -int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg); +int br_ioctl_stub(struct net *net, unsigned int cmd, void __user *uarg); /* br_multicast.c */ #ifdef CONFIG_BRIDGE_IGMP_SNOOPING diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c index 5cdbfbf9a7dc..def973eb496a 100644 --- a/net/core/dev_ioctl.c +++ b/net/core/dev_ioctl.c @@ -315,7 +315,6 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data, int err; struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name); const struct net_device_ops *ops; - netdevice_tracker dev_tracker; if (!dev) return -ENODEV; @@ -378,19 +377,6 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data, case SIOCWANDEV: return dev_siocwandev(dev, &ifr->ifr_settings); - case SIOCBRADDIF: - case SIOCBRDELIF: - if (!netif_device_present(dev)) - return -ENODEV; - if (!netif_is_bridge_master(dev)) - return -EOPNOTSUPP; - netdev_hold(dev, &dev_tracker, GFP_KERNEL); - rtnl_unlock(); - err = br_ioctl_call(net, netdev_priv(dev), cmd, ifr, NULL); - netdev_put(dev, &dev_tracker); - rtnl_lock(); - return err; - case SIOCSHWTSTAMP: err = net_hwtstamp_validate(ifr); if (err) @@ -575,8 +561,6 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr, case SIOCBONDRELEASE: case SIOCBONDSETHWADDR: case SIOCBONDCHANGEACTIVE: - case SIOCBRADDIF: - case SIOCBRDELIF: case SIOCSHWTSTAMP: if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) return -EPERM; diff --git a/net/socket.c b/net/socket.c index bd438b89e698..701389e2f22b 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1151,12 +1151,10 @@ static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from) */ static DEFINE_MUTEX(br_ioctl_mutex); -static int (*br_ioctl_hook)(struct net *net, struct net_bridge *br, - unsigned int cmd, struct ifreq *ifr, +static int (*br_ioctl_hook)(struct net *net, unsigned int cmd, void __user *uarg); -void brioctl_set(int (*hook)(struct net *net, struct net_bridge *br, - unsigned int cmd, struct ifreq *ifr, +void brioctl_set(int (*hook)(struct net *net, unsigned int cmd, void __user *uarg)) { mutex_lock(&br_ioctl_mutex); @@ -1165,8 +1163,7 @@ void brioctl_set(int (*hook)(struct net *net, struct net_bridge *br, } EXPORT_SYMBOL(brioctl_set); -int br_ioctl_call(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg) +int br_ioctl_call(struct net *net, unsigned int cmd, void __user *uarg) { int err = -ENOPKG; @@ -1175,7 +1172,7 @@ int br_ioctl_call(struct net *net, struct net_bridge *br, unsigned int cmd, mutex_lock(&br_ioctl_mutex); if (br_ioctl_hook) - err = br_ioctl_hook(net, br, cmd, ifr, uarg); + err = br_ioctl_hook(net, cmd, uarg); mutex_unlock(&br_ioctl_mutex); return err; @@ -1272,7 +1269,9 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg) case SIOCSIFBR: case SIOCBRADDBR: case SIOCBRDELBR: - err = br_ioctl_call(net, NULL, cmd, NULL, argp); + case SIOCBRADDIF: + case SIOCBRDELIF: + err = br_ioctl_call(net, cmd, argp); break; case SIOCGIFVLAN: case SIOCSIFVLAN: @@ -3376,6 +3375,8 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock, case SIOCGPGRP: case SIOCBRADDBR: case SIOCBRDELBR: + case SIOCBRADDIF: + case SIOCBRDELIF: case SIOCGIFVLAN: case SIOCSIFVLAN: case SIOCGSKNS: @@ -3415,8 +3416,6 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock, case SIOCGIFPFLAGS: case SIOCGIFTXQLEN: case SIOCSIFTXQLEN: - case SIOCBRADDIF: - case SIOCBRDELIF: case SIOCGIFNAME: case SIOCSIFNAME: case SIOCGMIIPHY: -- 2.47.3

2 days, 8 hours

[PATCH 6.6] net: Remove RTNL dance for SIOCBRADDIF and SIOCBRDELIF.

by Thadeu Lima de Souza Cascardo

commit ed3ba9b6e280e14cc3148c1b226ba453f02fa76c upstream. SIOCBRDELIF is passed to dev_ioctl() first and later forwarded to br_ioctl_call(), which causes unnecessary RTNL dance and the splat below [0] under RTNL pressure. Let's say Thread A is trying to detach a device from a bridge and Thread B is trying to remove the bridge. In dev_ioctl(), Thread A bumps the bridge device's refcnt by netdev_hold() and releases RTNL because the following br_ioctl_call() also re-acquires RTNL. In the race window, Thread B could acquire RTNL and try to remove the bridge device. Then, rtnl_unlock() by Thread B will release RTNL and wait for netdev_put() by Thread A. Thread A, however, must hold RTNL after the unlock in dev_ifsioc(), which may take long under RTNL pressure, resulting in the splat by Thread B. Thread A (SIOCBRDELIF) Thread B (SIOCBRDELBR) ---------------------- ---------------------- sock_ioctl sock_ioctl `- sock_do_ioctl `- br_ioctl_call `- dev_ioctl `- br_ioctl_stub |- rtnl_lock | |- dev_ifsioc ' ' |- dev = __dev_get_by_name(...) |- netdev_hold(dev, ...) . / |- rtnl_unlock ------. | | |- br_ioctl_call `---> |- rtnl_lock Race | | `- br_ioctl_stub |- br_del_bridge Window | | | |- dev = __dev_get_by_name(...) | | | May take long | `- br_dev_delete(dev, ...) | | | under RTNL pressure | `- unregister_netdevice_queue(dev, ...) | | | | `- rtnl_unlock \ | |- rtnl_lock <-' `- netdev_run_todo | |- ... `- netdev_run_todo | `- rtnl_unlock |- __rtnl_unlock | |- netdev_wait_allrefs_any |- netdev_put(dev, ...) <----------------' Wait refcnt decrement and log splat below To avoid blocking SIOCBRDELBR unnecessarily, let's not call dev_ioctl() for SIOCBRADDIF and SIOCBRDELIF. In the dev_ioctl() path, we do the following: 1. Copy struct ifreq by get_user_ifreq in sock_do_ioctl() 2. Check CAP_NET_ADMIN in dev_ioctl() 3. Call dev_load() in dev_ioctl() 4. Fetch the master dev from ifr.ifr_name in dev_ifsioc() 3. can be done by request_module() in br_ioctl_call(), so we move 1., 2., and 4. to br_ioctl_stub(). Note that 2. is also checked later in add_del_if(), but it's better performed before RTNL. SIOCBRADDIF and SIOCBRDELIF have been processed in dev_ioctl() since the pre-git era, and there seems to be no specific reason to process them there. [0]: unregister_netdevice: waiting for wpan3 to become free. Usage count = 2 ref_tracker: wpan3@ffff8880662d8608 has 1/1 users at __netdev_tracker_alloc include/linux/netdevice.h:4282 [inline] netdev_hold include/linux/netdevice.h:4311 [inline] dev_ifsioc+0xc6a/0x1160 net/core/dev_ioctl.c:624 dev_ioctl+0x255/0x10c0 net/core/dev_ioctl.c:826 sock_do_ioctl+0x1ca/0x260 net/socket.c:1213 sock_ioctl+0x23a/0x6c0 net/socket.c:1318 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x1a4/0x210 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcb/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 893b19587534 ("net: bridge: fix ioctl locking") Reported-by: syzkaller <syzkaller(a)googlegroups.com> Reported-by: yan kang <kangyan91(a)outlook.com> Reported-by: yue sun <samsun1006219(a)gmail.com> Closes: https://lore.kernel.org/netdev/SY8P300MB0421225D54EB92762AE8F0F2A1D32@SY8P3… Signed-off-by: Kuniyuki Iwashima <kuniyu(a)amazon.com> Acked-by: Stanislav Fomichev <sdf(a)fomichev.me> Reviewed-by: Ido Schimmel <idosch(a)nvidia.com> Acked-by: Nikolay Aleksandrov <razor(a)blackwall.org> Link: https://patch.msgid.link/20250316192851.19781-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni(a)redhat.com> [cascardo: fixed conflict at dev_ifsioc] Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo(a)igalia.com> --- include/linux/if_bridge.h | 6 ++---- net/bridge/br_ioctl.c | 36 +++++++++++++++++++++++++++++++++--- net/bridge/br_private.h | 3 +-- net/core/dev_ioctl.c | 16 ---------------- net/socket.c | 19 +++++++++---------- 5 files changed, 45 insertions(+), 35 deletions(-) diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h index 3ff96ae31bf6..c5fe3b2a53e8 100644 --- a/include/linux/if_bridge.h +++ b/include/linux/if_bridge.h @@ -65,11 +65,9 @@ struct br_ip_list { #define BR_DEFAULT_AGEING_TIME (300 * HZ) struct net_bridge; -void brioctl_set(int (*hook)(struct net *net, struct net_bridge *br, - unsigned int cmd, struct ifreq *ifr, +void brioctl_set(int (*hook)(struct net *net, unsigned int cmd, void __user *uarg)); -int br_ioctl_call(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg); +int br_ioctl_call(struct net *net, unsigned int cmd, void __user *uarg); #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING) int br_multicast_list_adjacent(struct net_device *dev, diff --git a/net/bridge/br_ioctl.c b/net/bridge/br_ioctl.c index f213ed108361..6bc0a11f2ed3 100644 --- a/net/bridge/br_ioctl.c +++ b/net/bridge/br_ioctl.c @@ -394,10 +394,26 @@ static int old_deviceless(struct net *net, void __user *data) return -EOPNOTSUPP; } -int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg) +int br_ioctl_stub(struct net *net, unsigned int cmd, void __user *uarg) { int ret = -EOPNOTSUPP; + struct ifreq ifr; + + if (cmd == SIOCBRADDIF || cmd == SIOCBRDELIF) { + void __user *data; + char *colon; + + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + if (get_user_ifreq(&ifr, &data, uarg)) + return -EFAULT; + + ifr.ifr_name[IFNAMSIZ - 1] = 0; + colon = strchr(ifr.ifr_name, ':'); + if (colon) + *colon = 0; + } rtnl_lock(); @@ -430,7 +446,21 @@ int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd, break; case SIOCBRADDIF: case SIOCBRDELIF: - ret = add_del_if(br, ifr->ifr_ifindex, cmd == SIOCBRADDIF); + { + struct net_device *dev; + + dev = __dev_get_by_name(net, ifr.ifr_name); + if (!dev || !netif_device_present(dev)) { + ret = -ENODEV; + break; + } + if (!netif_is_bridge_master(dev)) { + ret = -EOPNOTSUPP; + break; + } + + ret = add_del_if(netdev_priv(dev), ifr.ifr_ifindex, cmd == SIOCBRADDIF); + } break; } diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index c8a4e3b39b0e..7427ee6264b4 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -947,8 +947,7 @@ br_port_get_check_rtnl(const struct net_device *dev) /* br_ioctl.c */ int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq, void __user *data, int cmd); -int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg); +int br_ioctl_stub(struct net *net, unsigned int cmd, void __user *uarg); /* br_multicast.c */ #ifdef CONFIG_BRIDGE_IGMP_SNOOPING diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c index b46aedc36939..541d42bf1e40 100644 --- a/net/core/dev_ioctl.c +++ b/net/core/dev_ioctl.c @@ -517,7 +517,6 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data, int err; struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name); const struct net_device_ops *ops; - netdevice_tracker dev_tracker; if (!dev) return -ENODEV; @@ -580,19 +579,6 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data, case SIOCWANDEV: return dev_siocwandev(dev, &ifr->ifr_settings); - case SIOCBRADDIF: - case SIOCBRDELIF: - if (!netif_device_present(dev)) - return -ENODEV; - if (!netif_is_bridge_master(dev)) - return -EOPNOTSUPP; - netdev_hold(dev, &dev_tracker, GFP_KERNEL); - rtnl_unlock(); - err = br_ioctl_call(net, netdev_priv(dev), cmd, ifr, NULL); - netdev_put(dev, &dev_tracker); - rtnl_lock(); - return err; - case SIOCDEVPRIVATE ... SIOCDEVPRIVATE + 15: return dev_siocdevprivate(dev, ifr, data, cmd); @@ -773,8 +759,6 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr, case SIOCBONDRELEASE: case SIOCBONDSETHWADDR: case SIOCBONDCHANGEACTIVE: - case SIOCBRADDIF: - case SIOCBRDELIF: case SIOCSHWTSTAMP: if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) return -EPERM; diff --git a/net/socket.c b/net/socket.c index bad58f23f307..94c38c73fc69 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1168,12 +1168,10 @@ static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from) */ static DEFINE_MUTEX(br_ioctl_mutex); -static int (*br_ioctl_hook)(struct net *net, struct net_bridge *br, - unsigned int cmd, struct ifreq *ifr, +static int (*br_ioctl_hook)(struct net *net, unsigned int cmd, void __user *uarg); -void brioctl_set(int (*hook)(struct net *net, struct net_bridge *br, - unsigned int cmd, struct ifreq *ifr, +void brioctl_set(int (*hook)(struct net *net, unsigned int cmd, void __user *uarg)) { mutex_lock(&br_ioctl_mutex); @@ -1182,8 +1180,7 @@ void brioctl_set(int (*hook)(struct net *net, struct net_bridge *br, } EXPORT_SYMBOL(brioctl_set); -int br_ioctl_call(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg) +int br_ioctl_call(struct net *net, unsigned int cmd, void __user *uarg) { int err = -ENOPKG; @@ -1192,7 +1189,7 @@ int br_ioctl_call(struct net *net, struct net_bridge *br, unsigned int cmd, mutex_lock(&br_ioctl_mutex); if (br_ioctl_hook) - err = br_ioctl_hook(net, br, cmd, ifr, uarg); + err = br_ioctl_hook(net, cmd, uarg); mutex_unlock(&br_ioctl_mutex); return err; @@ -1292,7 +1289,9 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg) case SIOCSIFBR: case SIOCBRADDBR: case SIOCBRDELBR: - err = br_ioctl_call(net, NULL, cmd, NULL, argp); + case SIOCBRADDIF: + case SIOCBRDELIF: + err = br_ioctl_call(net, cmd, argp); break; case SIOCGIFVLAN: case SIOCSIFVLAN: @@ -3454,6 +3453,8 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock, case SIOCGPGRP: case SIOCBRADDBR: case SIOCBRDELBR: + case SIOCBRADDIF: + case SIOCBRDELIF: case SIOCGIFVLAN: case SIOCSIFVLAN: case SIOCGSKNS: @@ -3493,8 +3494,6 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock, case SIOCGIFPFLAGS: case SIOCGIFTXQLEN: case SIOCSIFTXQLEN: - case SIOCBRADDIF: - case SIOCBRDELIF: case SIOCGIFNAME: case SIOCSIFNAME: case SIOCGMIIPHY: -- 2.47.3

2 days, 8 hours

[PATCH 6.12] net: Remove RTNL dance for SIOCBRADDIF and SIOCBRDELIF.

by Thadeu Lima de Souza Cascardo

commit ed3ba9b6e280e14cc3148c1b226ba453f02fa76c upstream. SIOCBRDELIF is passed to dev_ioctl() first and later forwarded to br_ioctl_call(), which causes unnecessary RTNL dance and the splat below [0] under RTNL pressure. Let's say Thread A is trying to detach a device from a bridge and Thread B is trying to remove the bridge. In dev_ioctl(), Thread A bumps the bridge device's refcnt by netdev_hold() and releases RTNL because the following br_ioctl_call() also re-acquires RTNL. In the race window, Thread B could acquire RTNL and try to remove the bridge device. Then, rtnl_unlock() by Thread B will release RTNL and wait for netdev_put() by Thread A. Thread A, however, must hold RTNL after the unlock in dev_ifsioc(), which may take long under RTNL pressure, resulting in the splat by Thread B. Thread A (SIOCBRDELIF) Thread B (SIOCBRDELBR) ---------------------- ---------------------- sock_ioctl sock_ioctl `- sock_do_ioctl `- br_ioctl_call `- dev_ioctl `- br_ioctl_stub |- rtnl_lock | |- dev_ifsioc ' ' |- dev = __dev_get_by_name(...) |- netdev_hold(dev, ...) . / |- rtnl_unlock ------. | | |- br_ioctl_call `---> |- rtnl_lock Race | | `- br_ioctl_stub |- br_del_bridge Window | | | |- dev = __dev_get_by_name(...) | | | May take long | `- br_dev_delete(dev, ...) | | | under RTNL pressure | `- unregister_netdevice_queue(dev, ...) | | | | `- rtnl_unlock \ | |- rtnl_lock <-' `- netdev_run_todo | |- ... `- netdev_run_todo | `- rtnl_unlock |- __rtnl_unlock | |- netdev_wait_allrefs_any |- netdev_put(dev, ...) <----------------' Wait refcnt decrement and log splat below To avoid blocking SIOCBRDELBR unnecessarily, let's not call dev_ioctl() for SIOCBRADDIF and SIOCBRDELIF. In the dev_ioctl() path, we do the following: 1. Copy struct ifreq by get_user_ifreq in sock_do_ioctl() 2. Check CAP_NET_ADMIN in dev_ioctl() 3. Call dev_load() in dev_ioctl() 4. Fetch the master dev from ifr.ifr_name in dev_ifsioc() 3. can be done by request_module() in br_ioctl_call(), so we move 1., 2., and 4. to br_ioctl_stub(). Note that 2. is also checked later in add_del_if(), but it's better performed before RTNL. SIOCBRADDIF and SIOCBRDELIF have been processed in dev_ioctl() since the pre-git era, and there seems to be no specific reason to process them there. [0]: unregister_netdevice: waiting for wpan3 to become free. Usage count = 2 ref_tracker: wpan3@ffff8880662d8608 has 1/1 users at __netdev_tracker_alloc include/linux/netdevice.h:4282 [inline] netdev_hold include/linux/netdevice.h:4311 [inline] dev_ifsioc+0xc6a/0x1160 net/core/dev_ioctl.c:624 dev_ioctl+0x255/0x10c0 net/core/dev_ioctl.c:826 sock_do_ioctl+0x1ca/0x260 net/socket.c:1213 sock_ioctl+0x23a/0x6c0 net/socket.c:1318 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x1a4/0x210 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcb/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 893b19587534 ("net: bridge: fix ioctl locking") Reported-by: syzkaller <syzkaller(a)googlegroups.com> Reported-by: yan kang <kangyan91(a)outlook.com> Reported-by: yue sun <samsun1006219(a)gmail.com> Closes: https://lore.kernel.org/netdev/SY8P300MB0421225D54EB92762AE8F0F2A1D32@SY8P3… Signed-off-by: Kuniyuki Iwashima <kuniyu(a)amazon.com> Acked-by: Stanislav Fomichev <sdf(a)fomichev.me> Reviewed-by: Ido Schimmel <idosch(a)nvidia.com> Acked-by: Nikolay Aleksandrov <razor(a)blackwall.org> Link: https://patch.msgid.link/20250316192851.19781-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni(a)redhat.com> [cascardo: fixed conflict at dev_ifsioc] Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo(a)igalia.com> --- include/linux/if_bridge.h | 6 ++---- net/bridge/br_ioctl.c | 36 +++++++++++++++++++++++++++++++++--- net/bridge/br_private.h | 3 +-- net/core/dev_ioctl.c | 16 ---------------- net/socket.c | 19 +++++++++---------- 5 files changed, 45 insertions(+), 35 deletions(-) diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h index 3ff96ae31bf6..c5fe3b2a53e8 100644 --- a/include/linux/if_bridge.h +++ b/include/linux/if_bridge.h @@ -65,11 +65,9 @@ struct br_ip_list { #define BR_DEFAULT_AGEING_TIME (300 * HZ) struct net_bridge; -void brioctl_set(int (*hook)(struct net *net, struct net_bridge *br, - unsigned int cmd, struct ifreq *ifr, +void brioctl_set(int (*hook)(struct net *net, unsigned int cmd, void __user *uarg)); -int br_ioctl_call(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg); +int br_ioctl_call(struct net *net, unsigned int cmd, void __user *uarg); #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING) int br_multicast_list_adjacent(struct net_device *dev, diff --git a/net/bridge/br_ioctl.c b/net/bridge/br_ioctl.c index f213ed108361..6bc0a11f2ed3 100644 --- a/net/bridge/br_ioctl.c +++ b/net/bridge/br_ioctl.c @@ -394,10 +394,26 @@ static int old_deviceless(struct net *net, void __user *data) return -EOPNOTSUPP; } -int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg) +int br_ioctl_stub(struct net *net, unsigned int cmd, void __user *uarg) { int ret = -EOPNOTSUPP; + struct ifreq ifr; + + if (cmd == SIOCBRADDIF || cmd == SIOCBRDELIF) { + void __user *data; + char *colon; + + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + if (get_user_ifreq(&ifr, &data, uarg)) + return -EFAULT; + + ifr.ifr_name[IFNAMSIZ - 1] = 0; + colon = strchr(ifr.ifr_name, ':'); + if (colon) + *colon = 0; + } rtnl_lock(); @@ -430,7 +446,21 @@ int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd, break; case SIOCBRADDIF: case SIOCBRDELIF: - ret = add_del_if(br, ifr->ifr_ifindex, cmd == SIOCBRADDIF); + { + struct net_device *dev; + + dev = __dev_get_by_name(net, ifr.ifr_name); + if (!dev || !netif_device_present(dev)) { + ret = -ENODEV; + break; + } + if (!netif_is_bridge_master(dev)) { + ret = -EOPNOTSUPP; + break; + } + + ret = add_del_if(netdev_priv(dev), ifr.ifr_ifindex, cmd == SIOCBRADDIF); + } break; } diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 741b0b8c4bab..8c47af5c1dab 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -952,8 +952,7 @@ br_port_get_check_rtnl(const struct net_device *dev) /* br_ioctl.c */ int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq, void __user *data, int cmd); -int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg); +int br_ioctl_stub(struct net *net, unsigned int cmd, void __user *uarg); /* br_multicast.c */ #ifdef CONFIG_BRIDGE_IGMP_SNOOPING diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c index 473c437b6b53..81cd8df798c0 100644 --- a/net/core/dev_ioctl.c +++ b/net/core/dev_ioctl.c @@ -514,7 +514,6 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data, int err; struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name); const struct net_device_ops *ops; - netdevice_tracker dev_tracker; if (!dev) return -ENODEV; @@ -577,19 +576,6 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data, case SIOCWANDEV: return dev_siocwandev(dev, &ifr->ifr_settings); - case SIOCBRADDIF: - case SIOCBRDELIF: - if (!netif_device_present(dev)) - return -ENODEV; - if (!netif_is_bridge_master(dev)) - return -EOPNOTSUPP; - netdev_hold(dev, &dev_tracker, GFP_KERNEL); - rtnl_unlock(); - err = br_ioctl_call(net, netdev_priv(dev), cmd, ifr, NULL); - netdev_put(dev, &dev_tracker); - rtnl_lock(); - return err; - case SIOCDEVPRIVATE ... SIOCDEVPRIVATE + 15: return dev_siocdevprivate(dev, ifr, data, cmd); @@ -770,8 +756,6 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr, case SIOCBONDRELEASE: case SIOCBONDSETHWADDR: case SIOCBONDCHANGEACTIVE: - case SIOCBRADDIF: - case SIOCBRDELIF: case SIOCSHWTSTAMP: if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) return -EPERM; diff --git a/net/socket.c b/net/socket.c index 042451f01c65..a0f6f8b3376d 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1173,12 +1173,10 @@ static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from) */ static DEFINE_MUTEX(br_ioctl_mutex); -static int (*br_ioctl_hook)(struct net *net, struct net_bridge *br, - unsigned int cmd, struct ifreq *ifr, +static int (*br_ioctl_hook)(struct net *net, unsigned int cmd, void __user *uarg); -void brioctl_set(int (*hook)(struct net *net, struct net_bridge *br, - unsigned int cmd, struct ifreq *ifr, +void brioctl_set(int (*hook)(struct net *net, unsigned int cmd, void __user *uarg)) { mutex_lock(&br_ioctl_mutex); @@ -1187,8 +1185,7 @@ void brioctl_set(int (*hook)(struct net *net, struct net_bridge *br, } EXPORT_SYMBOL(brioctl_set); -int br_ioctl_call(struct net *net, struct net_bridge *br, unsigned int cmd, - struct ifreq *ifr, void __user *uarg) +int br_ioctl_call(struct net *net, unsigned int cmd, void __user *uarg) { int err = -ENOPKG; @@ -1197,7 +1194,7 @@ int br_ioctl_call(struct net *net, struct net_bridge *br, unsigned int cmd, mutex_lock(&br_ioctl_mutex); if (br_ioctl_hook) - err = br_ioctl_hook(net, br, cmd, ifr, uarg); + err = br_ioctl_hook(net, cmd, uarg); mutex_unlock(&br_ioctl_mutex); return err; @@ -1297,7 +1294,9 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg) case SIOCSIFBR: case SIOCBRADDBR: case SIOCBRDELBR: - err = br_ioctl_call(net, NULL, cmd, NULL, argp); + case SIOCBRADDIF: + case SIOCBRDELIF: + err = br_ioctl_call(net, cmd, argp); break; case SIOCGIFVLAN: case SIOCSIFVLAN: @@ -3466,6 +3465,8 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock, case SIOCGPGRP: case SIOCBRADDBR: case SIOCBRDELBR: + case SIOCBRADDIF: + case SIOCBRDELIF: case SIOCGIFVLAN: case SIOCSIFVLAN: case SIOCGSKNS: @@ -3505,8 +3506,6 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock, case SIOCGIFPFLAGS: case SIOCGIFTXQLEN: case SIOCSIFTXQLEN: - case SIOCBRADDIF: - case SIOCBRDELIF: case SIOCGIFNAME: case SIOCSIFNAME: case SIOCGMIIPHY: -- 2.47.3

2 days, 8 hours

FAILED: patch "[PATCH] drm/gma500: Remove unused helper psb_fbdev_fb_setcolreg()" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x be729f9de6c64240645dc80a24162ac4d3fe00a8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010536-thwarting-rare-1984@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From be729f9de6c64240645dc80a24162ac4d3fe00a8 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann <tzimmermann(a)suse.de> Date: Mon, 29 Sep 2025 10:23:23 +0200 Subject: [PATCH] drm/gma500: Remove unused helper psb_fbdev_fb_setcolreg() Remove psb_fbdev_fb_setcolreg(), which hasn't been called in almost a decade. Gma500 commit 4d8d096e9ae8 ("gma500: introduce the framebuffer support code") added the helper psb_fbdev_fb_setcolreg() for setting the fbdev palette via fbdev's fb_setcolreg callback. Later commit 3da6c2f3b730 ("drm/gma500: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops") set several default helpers for fbdev emulation, including fb_setcmap. The fbdev subsystem always prefers fb_setcmap over fb_setcolreg. [1] Hence, the gma500 code is no longer in use and gma500 has been using drm_fb_helper_setcmap() for several years without issues. Fixes: 3da6c2f3b730 ("drm/gma500: use DRM_FB_HELPER_DEFAULT_OPS for fb_ops") Cc: Patrik Jakobsson <patrik.r.jakobsson(a)gmail.com> Cc: Stefan Christ <contact(a)stefanchrist.eu> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: dri-devel(a)lists.freedesktop.org Cc: <stable(a)vger.kernel.org> # v4.10+ Link: https://elixir.bootlin.com/linux/v6.16.9/source/drivers/video/fbdev/core/fb… # [1] Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Acked-by: Patrik Jakobsson <patrik.r.jakobsson(a)gmail.com> Link: https://lore.kernel.org/r/20250929082338.18845-1-tzimmermann@suse.de diff --git a/drivers/gpu/drm/gma500/fbdev.c b/drivers/gpu/drm/gma500/fbdev.c index 32d31e5f5f1a..a6af21514cff 100644 --- a/drivers/gpu/drm/gma500/fbdev.c +++ b/drivers/gpu/drm/gma500/fbdev.c @@ -50,48 +50,6 @@ static const struct vm_operations_struct psb_fbdev_vm_ops = { * struct fb_ops */ -#define CMAP_TOHW(_val, _width) ((((_val) << (_width)) + 0x7FFF - (_val)) >> 16) - -static int psb_fbdev_fb_setcolreg(unsigned int regno, - unsigned int red, unsigned int green, - unsigned int blue, unsigned int transp, - struct fb_info *info) -{ - struct drm_fb_helper *fb_helper = info->par; - struct drm_framebuffer *fb = fb_helper->fb; - uint32_t v; - - if (!fb) - return -ENOMEM; - - if (regno > 255) - return 1; - - red = CMAP_TOHW(red, info->var.red.length); - blue = CMAP_TOHW(blue, info->var.blue.length); - green = CMAP_TOHW(green, info->var.green.length); - transp = CMAP_TOHW(transp, info->var.transp.length); - - v = (red << info->var.red.offset) | - (green << info->var.green.offset) | - (blue << info->var.blue.offset) | - (transp << info->var.transp.offset); - - if (regno < 16) { - switch (fb->format->cpp[0] * 8) { - case 16: - ((uint32_t *) info->pseudo_palette)[regno] = v; - break; - case 24: - case 32: - ((uint32_t *) info->pseudo_palette)[regno] = v; - break; - } - } - - return 0; -} - static int psb_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) { if (vma->vm_pgoff != 0) @@ -135,7 +93,6 @@ static const struct fb_ops psb_fbdev_fb_ops = { .owner = THIS_MODULE, __FB_DEFAULT_IOMEM_OPS_RDWR, DRM_FB_HELPER_DEFAULT_OPS, - .fb_setcolreg = psb_fbdev_fb_setcolreg, __FB_DEFAULT_IOMEM_OPS_DRAW, .fb_mmap = psb_fbdev_fb_mmap, .fb_destroy = psb_fbdev_fb_destroy,

2 days, 9 hours

[PATCH] tpm: Cap the number of PCR banks

by Jarkko Sakkinen

From: Jarkko Sakkinen <jarkko.sakkinen(a)opinsys.com> [ Upstream commit faf07e611dfa464b201223a7253e9dc5ee0f3c9e ] tpm2_get_pcr_allocation() does not cap any upper limit for the number of banks. Cap the limit to eight banks so that out of bounds values coming from external I/O cause on only limited harm. Cc: stable(a)vger.kernel.org # v5.10+ Fixes: bcfff8384f6c ("tpm: dynamically allocate the allocated_banks array") Tested-by: Lai Yi <yi1.lai(a)linux.intel.com> Reviewed-by: Jonathan McDowell <noodles(a)meta.com> Reviewed-by: Roberto Sassu <roberto.sassu(a)huawei.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen(a)opinsys.com> --- Backport for v5.10, v5.15, v6.1 and v6.6 drivers/char/tpm/tpm-chip.c | 1 - drivers/char/tpm/tpm1-cmd.c | 5 ----- drivers/char/tpm/tpm2-cmd.c | 8 +++----- include/linux/tpm.h | 8 +++++--- 4 files changed, 8 insertions(+), 14 deletions(-) diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 70e3fe20fdcf..458a3e9ea73a 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -279,7 +279,6 @@ static void tpm_dev_release(struct device *dev) kfree(chip->work_space.context_buf); kfree(chip->work_space.session_buf); - kfree(chip->allocated_banks); kfree(chip); } diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c index cf64c7385105..b49a790f1bd5 100644 --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -799,11 +799,6 @@ int tpm1_pm_suspend(struct tpm_chip *chip, u32 tpm_suspend_pcr) */ int tpm1_get_pcr_allocation(struct tpm_chip *chip) { - chip->allocated_banks = kcalloc(1, sizeof(*chip->allocated_banks), - GFP_KERNEL); - if (!chip->allocated_banks) - return -ENOMEM; - chip->allocated_banks[0].alg_id = TPM_ALG_SHA1; chip->allocated_banks[0].digest_size = hash_digest_size[HASH_ALGO_SHA1]; chip->allocated_banks[0].crypto_id = HASH_ALGO_SHA1; diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 93545be190a5..57bb3e34b770 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -574,11 +574,9 @@ ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) nr_possible_banks = be32_to_cpup( (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]); - - chip->allocated_banks = kcalloc(nr_possible_banks, - sizeof(*chip->allocated_banks), - GFP_KERNEL); - if (!chip->allocated_banks) { + if (nr_possible_banks > TPM2_MAX_PCR_BANKS) { + pr_err("tpm: out of bank capacity: %u > %u\n", + nr_possible_banks, TPM2_MAX_PCR_BANKS); rc = -ENOMEM; goto out; } diff --git a/include/linux/tpm.h b/include/linux/tpm.h index bf8a4ec8a01c..f5e7cca2f257 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -25,7 +25,9 @@ #include <crypto/hash_info.h> #define TPM_DIGEST_SIZE 20 /* Max TPM v1.2 PCR size */ -#define TPM_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE + +#define TPM2_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE +#define TPM2_MAX_PCR_BANKS 8 struct tpm_chip; struct trusted_key_payload; @@ -51,7 +53,7 @@ enum tpm_algorithms { struct tpm_digest { u16 alg_id; - u8 digest[TPM_MAX_DIGEST_SIZE]; + u8 digest[TPM2_MAX_DIGEST_SIZE]; } __packed; struct tpm_bank_info { @@ -157,7 +159,7 @@ struct tpm_chip { unsigned int groups_cnt; u32 nr_allocated_banks; - struct tpm_bank_info *allocated_banks; + struct tpm_bank_info allocated_banks[TPM2_MAX_PCR_BANKS]; #ifdef CONFIG_ACPI acpi_handle acpi_dev_handle; char ppi_version[TPM_PPI_VERSION_LEN + 1]; -- 2.52.0

2 days, 9 hours

FAILED: patch "[PATCH] drm/tilcdc: Fix removal actions in case of failed probe" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x a585c7ef9cabda58088916baedc6573e9a5cd2a7 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2026010530-discard-saggy-15cd@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From a585c7ef9cabda58088916baedc6573e9a5cd2a7 Mon Sep 17 00:00:00 2001 From: "Kory Maincent (TI.com)" <kory.maincent(a)bootlin.com> Date: Tue, 25 Nov 2025 10:05:44 +0100 Subject: [PATCH] drm/tilcdc: Fix removal actions in case of failed probe The drm_kms_helper_poll_fini() and drm_atomic_helper_shutdown() helpers should only be called when the device has been successfully registered. Currently, these functions are called unconditionally in tilcdc_fini(), which causes warnings during probe deferral scenarios. [ 7.972317] WARNING: CPU: 0 PID: 23 at drivers/gpu/drm/drm_atomic_state_helper.c:175 drm_atomic_helper_crtc_duplicate_state+0x60/0x68 ... [ 8.005820] drm_atomic_helper_crtc_duplicate_state from drm_atomic_get_crtc_state+0x68/0x108 [ 8.005858] drm_atomic_get_crtc_state from drm_atomic_helper_disable_all+0x90/0x1c8 [ 8.005885] drm_atomic_helper_disable_all from drm_atomic_helper_shutdown+0x90/0x144 [ 8.005911] drm_atomic_helper_shutdown from tilcdc_fini+0x68/0xf8 [tilcdc] [ 8.005957] tilcdc_fini [tilcdc] from tilcdc_pdev_probe+0xb0/0x6d4 [tilcdc] Fix this by rewriting the failed probe cleanup path using the standard goto error handling pattern, which ensures that cleanup functions are only called on successfully initialized resources. Additionally, remove the now-unnecessary is_registered flag. Cc: stable(a)vger.kernel.org Fixes: 3c4babae3c4a ("drm: Call drm_atomic_helper_shutdown() at shutdown/remove time for misc drivers") Signed-off-by: Kory Maincent (TI.com) <kory.maincent(a)bootlin.com> Reviewed-by: Douglas Anderson <dianders(a)chromium.org> Reviewed-by: Luca Ceresoli <luca.ceresoli(a)bootlin.com> Signed-off-by: Douglas Anderson <dianders(a)chromium.org> Link: https://patch.msgid.link/20251125090546.137193-1-kory.maincent@bootlin.com diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c index b5f60b2b2d0e..41802c9bd147 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c @@ -586,7 +586,7 @@ static void tilcdc_crtc_recover_work(struct work_struct *work) drm_modeset_unlock(&crtc->mutex); } -static void tilcdc_crtc_destroy(struct drm_crtc *crtc) +void tilcdc_crtc_destroy(struct drm_crtc *crtc) { struct tilcdc_drm_private *priv = crtc->dev->dev_private; diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c index 7caec4d38ddf..3dcbec312bac 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c @@ -172,8 +172,7 @@ static void tilcdc_fini(struct drm_device *dev) if (priv->crtc) tilcdc_crtc_shutdown(priv->crtc); - if (priv->is_registered) - drm_dev_unregister(dev); + drm_dev_unregister(dev); drm_kms_helper_poll_fini(dev); drm_atomic_helper_shutdown(dev); @@ -220,21 +219,21 @@ static int tilcdc_init(const struct drm_driver *ddrv, struct device *dev) priv->wq = alloc_ordered_workqueue("tilcdc", 0); if (!priv->wq) { ret = -ENOMEM; - goto init_failed; + goto put_drm; } priv->mmio = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(priv->mmio)) { dev_err(dev, "failed to request / ioremap\n"); ret = PTR_ERR(priv->mmio); - goto init_failed; + goto free_wq; } priv->clk = clk_get(dev, "fck"); if (IS_ERR(priv->clk)) { dev_err(dev, "failed to get functional clock\n"); ret = -ENODEV; - goto init_failed; + goto free_wq; } pm_runtime_enable(dev); @@ -313,7 +312,7 @@ static int tilcdc_init(const struct drm_driver *ddrv, struct device *dev) ret = tilcdc_crtc_create(ddev); if (ret < 0) { dev_err(dev, "failed to create crtc\n"); - goto init_failed; + goto disable_pm; } modeset_init(ddev); @@ -324,46 +323,46 @@ static int tilcdc_init(const struct drm_driver *ddrv, struct device *dev) if (ret) { dev_err(dev, "failed to register cpufreq notifier\n"); priv->freq_transition.notifier_call = NULL; - goto init_failed; + goto destroy_crtc; } #endif if (priv->is_componentized) { ret = component_bind_all(dev, ddev); if (ret < 0) - goto init_failed; + goto unregister_cpufreq_notif; ret = tilcdc_add_component_encoder(ddev); if (ret < 0) - goto init_failed; + goto unbind_component; } else { ret = tilcdc_attach_external_device(ddev); if (ret) - goto init_failed; + goto unregister_cpufreq_notif; } if (!priv->external_connector && ((priv->num_encoders == 0) || (priv->num_connectors == 0))) { dev_err(dev, "no encoders/connectors found\n"); ret = -EPROBE_DEFER; - goto init_failed; + goto unbind_component; } ret = drm_vblank_init(ddev, 1); if (ret < 0) { dev_err(dev, "failed to initialize vblank\n"); - goto init_failed; + goto unbind_component; } ret = platform_get_irq(pdev, 0); if (ret < 0) - goto init_failed; + goto unbind_component; priv->irq = ret; ret = tilcdc_irq_install(ddev, priv->irq); if (ret < 0) { dev_err(dev, "failed to install IRQ handler\n"); - goto init_failed; + goto unbind_component; } drm_mode_config_reset(ddev); @@ -372,16 +371,34 @@ static int tilcdc_init(const struct drm_driver *ddrv, struct device *dev) ret = drm_dev_register(ddev, 0); if (ret) - goto init_failed; - priv->is_registered = true; + goto stop_poll; drm_client_setup_with_color_mode(ddev, bpp); return 0; -init_failed: - tilcdc_fini(ddev); +stop_poll: + drm_kms_helper_poll_fini(ddev); + tilcdc_irq_uninstall(ddev); +unbind_component: + if (priv->is_componentized) + component_unbind_all(dev, ddev); +unregister_cpufreq_notif: +#ifdef CONFIG_CPU_FREQ + cpufreq_unregister_notifier(&priv->freq_transition, + CPUFREQ_TRANSITION_NOTIFIER); +destroy_crtc: +#endif + tilcdc_crtc_destroy(priv->crtc); +disable_pm: + pm_runtime_disable(dev); + clk_put(priv->clk); +free_wq: + destroy_workqueue(priv->wq); +put_drm: platform_set_drvdata(pdev, NULL); + ddev->dev_private = NULL; + drm_dev_put(ddev); return ret; } diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.h b/drivers/gpu/drm/tilcdc/tilcdc_drv.h index b818448c83f6..58b276f82a66 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.h +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.h @@ -82,7 +82,6 @@ struct tilcdc_drm_private { struct drm_encoder *external_encoder; struct drm_connector *external_connector; - bool is_registered; bool is_componentized; bool irq_enabled; }; @@ -164,6 +163,7 @@ void tilcdc_crtc_set_panel_info(struct drm_crtc *crtc, void tilcdc_crtc_set_simulate_vesa_sync(struct drm_crtc *crtc, bool simulate_vesa_sync); void tilcdc_crtc_shutdown(struct drm_crtc *crtc); +void tilcdc_crtc_destroy(struct drm_crtc *crtc); int tilcdc_crtc_update_fb(struct drm_crtc *crtc, struct drm_framebuffer *fb, struct drm_pending_vblank_event *event);

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