This is the start of the stable review cycle for the 6.6.99 release. There are 111 patches in this series, all will be posted as a response to this one. If anyone has any issues with these being applied, please let me know.

Responses should be made by Thu, 17 Jul 2025 16:35:12 +0000. Anything received after that time might be too late.

The whole patch series can be found in one patch at: https://www.kernel.org/pub/linux/kernel/v6.x/stable-review/patch-6.6.99-rc2.... or in the git tree and branch at: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-6.6.y and the diffstat can be found below.

thanks,

greg k-h

------------- Pseudo-Shortlog of commits:

Greg Kroah-Hartman gregkh@linuxfoundation.org Linux 6.6.99-rc2

Michael Jeanson mjeanson@efficios.com rseq: Fix segfault on registration when rseq_cs is non-zero

Lukas Wunner lukas@wunner.de crypto: ecdsa - Harden against integer overflows in DIV_ROUND_UP()

Namjae Jeon linkinjeon@kernel.org ksmbd: fix potential use-after-free in oplock/lease break ack

Yeoreum Yun yeoreum.yun@arm.com kasan: remove kasan_find_vm_area() to prevent possible deadlock

Paulo Alcantara pc@manguebit.com smb: client: fix potential race in cifs_put_tcon()

Willem de Bruijn willemb@google.com selftests/bpf: adapt one more case in test_lru_map to the new target_free

Hans de Goede hdegoede@redhat.com Input: atkbd - do not skip atkbd_deactivate() when skipping ATKBD_CMD_GETID

Chia-Lin Kao (AceLan) acelan.kao@canonical.com HID: quirks: Add quirk for 2 Chicony Electronics HP 5MP Cameras

Zhang Heng zhangheng@kylinos.cn HID: Add IGNORE quirk for SMARTLINKTECHNOLOGY

Willem de Bruijn willemb@google.com bpf: Adjust free target to avoid global starvation of LRU map

Nicolas Pitre npitre@baylibre.com vt: add missing notification when switching back to text mode

Filipe Manana fdmanana@suse.com btrfs: fix assertion when building free space tree

Long Li longli@microsoft.com net: mana: Record doorbell physical address in PF mode

Akira Inoue niyarium@gmail.com HID: lenovo: Add support for ThinkPad X1 Tablet Thin Keyboard Gen2

Xiaowei Li xiaowei.li@simcom.com net: usb: qmi_wwan: add SIMCom 8230C composition

Yasmin Fitzgerald sunoflife1.git@gmail.com ALSA: hda/realtek - Enable mute LED on HP Pavilion Laptop 15-eg100

Yuzuru10 yuzuru_10@proton.me ASoC: amd: yc: add quirk for Acer Nitro ANV15-41 internal mic

Fengnan Chang changfengnan@bytedance.com io_uring: make fallocate be hashed work

Tiwei Bie tiwei.btw@antgroup.com um: vector: Reduce stack usage in vector_eth_configure()

Thomas Fourier fourier.thomas@gmail.com atm: idt77252: Add missing `dma_map_error()`

Ronnie Sahlberg rsahlberg@whamcloud.com ublk: sanity check add_dev input for underflow

Somnath Kotur somnath.kotur@broadcom.com bnxt_en: Set DMA unmap len correctly for XDP_REDIRECT

Shravya KN shravya.k-n@broadcom.com bnxt_en: Fix DCB ETS validation

Alok Tiwari alok.a.tiwari@oracle.com net: ll_temac: Fix missing tx_pending check in ethtools_set_ringparam()

Sean Nyekjaer sean@geanix.com can: m_can: m_can_handle_lost_msg(): downgrade msg lost in rx message to debug level

Oleksij Rempel o.rempel@pengutronix.de net: phy: microchip: limit 100M workaround to link-down events on LAN88xx

Mingming Cao mmc@linux.ibm.com ibmvnic: Fix hardcoded NUM_RX_STATS/NUM_TX_STATS with dynamic sizeof

Kito Xu veritas501@foxmail.com net: appletalk: Fix device refcount leak in atrtr_create()

Eric Dumazet edumazet@google.com netfilter: flowtable: account for Ethernet header in nf_flow_pppoe_proto()

Zheng Qixing zhengqixing@huawei.com nbd: fix uaf in nbd_genl_connect() error path

Nigel Croxon ncroxon@redhat.com raid10: cleanup memleak at raid10_make_request

Wang Jinchao wangjinchao600@gmail.com md/raid1: Fix stack memory use after return in raid1_reshape

Mikko Perttunen mperttunen@nvidia.com drm/tegra: nvdec: Fix dma_alloc_coherent error check

Daniil Dulov d.dulov@aladdin.ru wifi: zd1211rw: Fix potential NULL pointer dereference in zd_mac_tx_to_dev()

Shyam Prasad N sprasad@microsoft.com cifs: all initializations for tcon should happen in tcon_info_alloc

Paulo Alcantara pc@manguebit.com smb: client: fix DFS interlink failover

Paulo Alcantara pc@manguebit.com smb: client: avoid unnecessary reconnects when refreshing referrals

Kuen-Han Tsai khtsai@google.com usb: dwc3: Abort suspend on soft disconnect failure

Pawel Laszczak pawell@cadence.com usb: cdnsp: Fix issue with CV Bad Descriptor test

Lee Jones lee@kernel.org usb: cdnsp: Replace snprintf() with the safer scnprintf() variant

Pawel Laszczak pawell@cadence.com usb:cdnsp: remove TRB_FLUSH_ENDPOINT command

Filipe Manana fdmanana@suse.com btrfs: fix inode lookup error handling during log replay

Filipe Manana fdmanana@suse.com btrfs: return a btrfs_inode from btrfs_iget_logging()

Filipe Manana fdmanana@suse.com btrfs: remove redundant root argument from fixup_inode_link_count()

Filipe Manana fdmanana@suse.com btrfs: remove redundant root argument from btrfs_update_inode_fallback()

Filipe Manana fdmanana@suse.com btrfs: remove noinline from btrfs_update_inode()

Jakub Kicinski kuba@kernel.org netlink: make sure we allow at least one dump skb

Kuniyuki Iwashima kuniyu@google.com netlink: Fix rmem check in netlink_broadcast_deliver().

Chao Yu chao@kernel.org erofs: fix to add missing tracepoint in erofs_read_folio()

Al Viro viro@zeniv.linux.org.uk ksmbd: fix a mount write count leak in ksmbd_vfs_kern_path_locked()

Stefan Metzmacher metze@samba.org smb: server: make use of rdma_destroy_qp()

Jann Horn jannh@google.com x86/mm: Disable hugetlb page table sharing on 32-bit

Mikhail Paulyshka me@mixaill.net x86/rdrand: Disable RDSEED on AMD Cyan Skillfish

Uwe Kleine-König u.kleine-koenig@baylibre.com pwm: mediatek: Ensure to disable clocks in error path

Alexander Gordeev agordeev@linux.ibm.com mm/vmalloc: leave lazy MMU mode on PTE mapping error

Florian Fainelli florian.fainelli@broadcom.com scripts/gdb: fix interrupts.py after maple tree conversion

Florian Fainelli florian.fainelli@broadcom.com scripts/gdb: de-reference per-CPU MCE interrupts

Florian Fainelli florian.fainelli@broadcom.com scripts/gdb: fix interrupts display after MCP on x86

Baolin Wang baolin.wang@linux.alibaba.com mm: fix the inaccurate memory statistics issue for users

Wei Yang richard.weiyang@gmail.com maple_tree: fix mt_destroy_walk() on root leaf node

Achill Gilgenast fossdd@pwned.life kallsyms: fix build without execinfo

Rafael J. Wysocki rafael.j.wysocki@intel.com Revert "ACPI: battery: negate current when discharging"

Thomas Zimmermann tzimmermann@suse.de drm/framebuffer: Acquire internal references on GEM handles

Kuen-Han Tsai khtsai@google.com Revert "usb: gadget: u_serial: Add null pointer check in gs_start_io"

Kuen-Han Tsai khtsai@google.com usb: gadget: u_serial: Fix race condition in TTY wakeup

Simona Vetter simona.vetter@ffwll.ch drm/gem: Fix race in drm_gem_handle_create_tail()

Christian König christian.koenig@amd.com drm/ttm: fix error handling in ttm_buffer_object_transfer

Matthew Brost matthew.brost@intel.com drm/sched: Increment job count before swapping tail spsc queue

Thomas Zimmermann tzimmermann@suse.de drm/gem: Acquire references on GEM handles for framebuffers

Mathy Vanhoef Mathy.Vanhoef@kuleuven.be wifi: prevent A-MSDU attacks in mesh networks

Bartosz Golaszewski bartosz.golaszewski@linaro.org pinctrl: qcom: msm: mark certain pins as invalid for interrupts

Håkon Bugge haakon.bugge@oracle.com md/md-bitmap: fix GPF in bitmap_get_stats()

Guillaume Nault gnault@redhat.com gre: Fix IPv6 multicast route creation.

Sean Christopherson seanjc@google.com KVM: SVM: Reject SEV{-ES} intra host migration if vCPU creation is in-flight

David Woodhouse dwmw@amazon.co.uk KVM: x86/xen: Allow 'out of range' event channel ports in IRQ routing table.

JP Kobryn inwardvessel@gmail.com x86/mce: Make sure CMCI banks are cleared during shutdown on Intel

Yazen Ghannam yazen.ghannam@amd.com x86/mce: Don't remove sysfs if thresholding sysfs init fails

Yazen Ghannam yazen.ghannam@amd.com x86/mce/amd: Fix threshold limit reset

Yazen Ghannam yazen.ghannam@amd.com x86/mce/amd: Add default names for MCA banks and blocks

Dan Carpenter dan.carpenter@linaro.org ipmi:msghandler: Fix potential memory corruption in ipmi_create_user()

David Howells dhowells@redhat.com rxrpc: Fix oops due to non-existence of prealloc backlog struct

Christian Eggers ceggers@arri.de Bluetooth: HCI: Set extended advertising data synchronously

Leo Yan leo.yan@arm.com perf: build: Setup PKG_CONFIG_LIBDIR for cross compilation

Liam R. Howlett Liam.Howlett@oracle.com maple_tree: fix MA_STATE_PREALLOC flag in mas_preallocate()

David Howells dhowells@redhat.com rxrpc: Fix bug due to prealloc collision

Victor Nogueira victor@mojatatu.com net/sched: Abort __tc_modify_qdisc if parent class does not exist

Yue Haibing yuehaibing@huawei.com atm: clip: Fix NULL pointer dereference in vcc_sendmsg()

Kuniyuki Iwashima kuniyu@google.com atm: clip: Fix infinite recursive call of clip_push().

Kuniyuki Iwashima kuniyu@google.com atm: clip: Fix memory leak of struct clip_vcc.

Kuniyuki Iwashima kuniyu@google.com atm: clip: Fix potential null-ptr-deref in to_atmarpd().

Oleksij Rempel o.rempel@pengutronix.de net: phy: smsc: Fix link failure in forced mode with Auto-MDIX

Oleksij Rempel o.rempel@pengutronix.de net: phy: smsc: Force predictable MDI-X state on LAN87xx

Oleksij Rempel o.rempel@pengutronix.de net: phy: smsc: Fix Auto-MDIX configuration when disabled by strap

EricChan chenchuangyu@xiaomi.com net: stmmac: Fix interrupt handling for level-triggered mode in DWC_XGMAC2

Michal Luczaj mhal@rbox.co vsock: Fix IOCTL_VM_SOCKETS_GET_LOCAL_CID to check also `transport_local`

Michal Luczaj mhal@rbox.co vsock: Fix transport_* TOCTOU

Michal Luczaj mhal@rbox.co vsock: Fix transport_{g2h,h2g} TOCTOU

Jiayuan Chen jiayuan.chen@linux.dev tcp: Correct signedness in skb remaining space calculation

Kuniyuki Iwashima kuniyu@google.com tipc: Fix use-after-free in tipc_conn_close().

Stefano Garzarella sgarzare@redhat.com vsock: fix `vsock_proto` declaration

Kuniyuki Iwashima kuniyu@google.com netlink: Fix wraparounds of sk->sk_rmem_alloc.

Al Viro viro@zeniv.linux.org.uk fix proc_sys_compare() handling of in-lookup dentries

Mario Limonciello mario.limonciello@amd.com pinctrl: amd: Clear GPIO debounce for suspend

Luiz Augusto von Dentz luiz.von.dentz@intel.com Bluetooth: hci_event: Fix not marking Broadcast Sink BIS as connected

Luiz Augusto von Dentz luiz.von.dentz@intel.com Bluetooth: hci_sync: Fix not disabling advertising instance

Richard Fitzgerald rf@opensource.cirrus.com ASoC: cs35l56: probe() should fail if the device ID is not recognized

Peter Zijlstra peterz@infradead.org perf: Revert to requiring CAP_SYS_ADMIN for uprobes

Luo Gengkun luogengkun@huaweicloud.com perf/core: Fix the WARN_ON_ONCE is out of lock protected region

Shengjiu Wang shengjiu.wang@nxp.com ASoC: fsl_asrc: use internal measured ratio for non-ideal ratio mode

Kaustabh Chakraborty kauschluss@disroot.org drm/exynos: exynos7_drm_decon: add vblank check in IRQ handling

Linus Torvalds torvalds@linux-foundation.org eventpoll: don't decrement ep refcount while still holding the ep mutex

-------------

Diffstat:

Documentation/bpf/map_hash.rst | 8 +- Documentation/bpf/map_lru_hash_update.dot | 6 +- Makefile | 4 +- arch/um/drivers/vector_kern.c | 42 +-- arch/x86/Kconfig | 2 +- arch/x86/include/asm/msr-index.h | 1 + arch/x86/kernel/cpu/amd.c | 7 + arch/x86/kernel/cpu/mce/amd.c | 28 +- arch/x86/kernel/cpu/mce/core.c | 8 +- arch/x86/kernel/cpu/mce/intel.c | 1 + arch/x86/kvm/svm/sev.c | 4 + arch/x86/kvm/xen.c | 15 +- crypto/ecc.c | 2 +- drivers/acpi/battery.c | 19 +- drivers/atm/idt77252.c | 5 + drivers/block/nbd.c | 6 +- drivers/block/ublk_drv.c | 3 +- drivers/char/ipmi/ipmi_msghandler.c | 3 +- drivers/gpu/drm/drm_framebuffer.c | 31 +- drivers/gpu/drm/drm_gem.c | 74 ++++- drivers/gpu/drm/drm_internal.h | 2 + drivers/gpu/drm/exynos/exynos7_drm_decon.c | 4 + drivers/gpu/drm/tegra/nvdec.c | 6 +- drivers/gpu/drm/ttm/ttm_bo_util.c | 13 +- drivers/hid/hid-ids.h | 6 + drivers/hid/hid-lenovo.c | 8 + drivers/hid/hid-multitouch.c | 8 +- drivers/hid/hid-quirks.c | 3 + drivers/input/keyboard/atkbd.c | 3 +- drivers/md/md-bitmap.c | 3 +- drivers/md/raid1.c | 1 + drivers/md/raid10.c | 10 +- drivers/net/can/m_can/m_can.c | 2 +- drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c | 2 + drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c | 2 +- drivers/net/ethernet/ibm/ibmvnic.h | 8 +- drivers/net/ethernet/microsoft/mana/gdma_main.c | 3 + drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c | 24 +- drivers/net/ethernet/xilinx/ll_temac_main.c | 2 +- drivers/net/phy/microchip.c | 2 +- drivers/net/phy/smsc.c | 57 +++- drivers/net/usb/qmi_wwan.c | 1 + drivers/net/wireless/zydas/zd1211rw/zd_mac.c | 6 +- drivers/pinctrl/pinctrl-amd.c | 11 + drivers/pinctrl/qcom/pinctrl-msm.c | 20 ++ drivers/pwm/pwm-mediatek.c | 13 +- drivers/tty/vt/vt.c | 1 + drivers/usb/cdns3/cdnsp-debug.h | 358 ++++++++++----------- drivers/usb/cdns3/cdnsp-ep0.c | 18 +- drivers/usb/cdns3/cdnsp-gadget.c | 6 +- drivers/usb/cdns3/cdnsp-gadget.h | 11 +- drivers/usb/cdns3/cdnsp-ring.c | 27 +- drivers/usb/dwc3/core.c | 9 +- drivers/usb/dwc3/gadget.c | 22 +- drivers/usb/gadget/function/u_serial.c | 12 +- fs/btrfs/btrfs_inode.h | 2 +- fs/btrfs/free-space-tree.c | 16 +- fs/btrfs/inode.c | 18 +- fs/btrfs/transaction.c | 2 +- fs/btrfs/tree-log.c | 331 +++++++++++-------- fs/erofs/data.c | 2 + fs/eventpoll.c | 12 +- fs/proc/inode.c | 2 +- fs/proc/proc_sysctl.c | 18 +- fs/proc/task_mmu.c | 14 +- fs/smb/client/cifsglob.h | 3 + fs/smb/client/cifsproto.h | 13 +- fs/smb/client/connect.c | 47 ++- fs/smb/client/dfs.c | 73 ++--- fs/smb/client/dfs.h | 42 ++- fs/smb/client/dfs_cache.c | 198 +++++++----- fs/smb/client/fs_context.h | 1 + fs/smb/client/misc.c | 9 + fs/smb/client/namespace.c | 2 +- fs/smb/server/smb2pdu.c | 29 +- fs/smb/server/transport_rdma.c | 5 +- fs/smb/server/vfs.c | 1 + include/drm/drm_file.h | 3 + include/drm/drm_framebuffer.h | 7 + include/drm/spsc_queue.h | 4 +- include/linux/math.h | 12 + include/linux/mm.h | 5 + include/net/af_vsock.h | 2 +- include/net/netfilter/nf_flow_table.h | 2 +- io_uring/opdef.c | 1 + kernel/bpf/bpf_lru_list.c | 9 +- kernel/bpf/bpf_lru_list.h | 1 + kernel/events/core.c | 6 +- kernel/rseq.c | 60 +++- lib/maple_tree.c | 14 +- mm/kasan/report.c | 13 +- mm/vmalloc.c | 22 +- net/appletalk/ddp.c | 1 + net/atm/clip.c | 64 +++- net/bluetooth/hci_event.c | 39 +-- net/bluetooth/hci_sync.c | 215 ++++++++----- net/ipv4/tcp.c | 2 +- net/ipv6/addrconf.c | 9 +- net/netlink/af_netlink.c | 90 +++--- net/rxrpc/call_accept.c | 4 + net/sched/sch_api.c | 23 +- net/tipc/topsrv.c | 2 + net/vmw_vsock/af_vsock.c | 57 +++- net/wireless/util.c | 52 ++- scripts/gdb/linux/constants.py.in | 7 + scripts/gdb/linux/interrupts.py | 16 +- scripts/gdb/linux/mapletree.py | 252 +++++++++++++++ scripts/gdb/linux/xarray.py | 28 ++ sound/pci/hda/patch_realtek.c | 1 + sound/soc/amd/yc/acp6x-mach.c | 7 + sound/soc/codecs/cs35l56-shared.c | 2 +- sound/soc/fsl/fsl_asrc.c | 3 +- tools/arch/x86/include/asm/msr-index.h | 1 + tools/build/feature/Makefile | 25 +- tools/include/linux/kallsyms.h | 4 + tools/perf/Makefile.perf | 27 +- tools/testing/selftests/bpf/test_lru_map.c | 105 +++--- 117 files changed, 1948 insertions(+), 1042 deletions(-)

From gregkh@linuxfoundation.org Tue Jul 15 18:35:42 2025 Message-ID: 20250715163542.121531643@linuxfoundation.org User-Agent: quilt/0.68 Date: Tue, 15 Jul 2025 18:35:43 +0200 From: Greg Kroah-Hartman gregkh@linuxfoundation.org To: stable@vger.kernel.org Cc: patches@lists.linux.dev, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, linux@roeck-us.net, shuah@kernel.org, patches@kernelci.org, lkft-triage@lists.linaro.org, pavel@denx.de, jonathanh@nvidia.com, f.fainelli@gmail.com, sudipm.mukherjee@gmail.com, srw@sladewatkins.net, rwarsow@gmx.de, conor@kernel.org, hargar@microsoft.com, broonie@kernel.org, Jann Horn jannh@google.com, Alexander Viro viro@zeniv.linux.org.uk, Christian Brauner brauner@kernel.org, Jan Kara jack@suse.cz, Linus Torvalds torvalds@linux-foundation.org X-stable: review X-Patchwork-Hint: ignore Subject: [PATCH 6.6 001/111] eventpoll: dont decrement ep refcount while still holding the ep mutex MIME-Version: 1.0

6.6-stable review patch. If anyone has any objections, please let me know.

------------------

From: Linus Torvalds torvalds@linux-foundation.org

commit 8c2e52ebbe885c7eeaabd3b7ddcdc1246fc400d2 upstream.

Jann Horn points out that epoll is decrementing the ep refcount and then doing a

mutex_unlock(&ep->mtx);

afterwards. That's very wrong, because it can lead to a use-after-free.

That pattern is actually fine for the very last reference, because the code in question will delay the actual call to "ep_free(ep)" until after it has unlocked the mutex.

But it's wrong for the much subtler "next to last" case when somebody *else* may also be dropping their reference and free the ep while we're still using the mutex.

Note that this is true even if that other user is also using the same ep mutex: mutexes, unlike spinlocks, can not be used for object ownership, even if they guarantee mutual exclusion.

A mutex "unlock" operation is not atomic, and as one user is still accessing the mutex as part of unlocking it, another user can come in and get the now released mutex and free the data structure while the first user is still cleaning up.

See our mutex documentation in Documentation/locking/mutex-design.rst, in particular the section [1] about semantics:

"mutex_unlock() may access the mutex structure even after it has internally released the lock already - so it's not safe for another context to acquire the mutex and assume that the mutex_unlock() context is not using the structure anymore"

So if we drop our ep ref before the mutex unlock, but we weren't the last one, we may then unlock the mutex, another user comes in, drops _their_ reference and releases the 'ep' as it now has no users - all while the mutex_unlock() is still accessing it.

Fix this by simply moving the ep refcount dropping to outside the mutex: the refcount itself is atomic, and doesn't need mutex protection (that's the whole _point_ of refcounts: unlike mutexes, they are inherently about object lifetimes).

Reported-by: Jann Horn jannh@google.com Link: https://docs.kernel.org/locking/mutex-design.html#semantics [1] Cc: Alexander Viro viro@zeniv.linux.org.uk Cc: Christian Brauner brauner@kernel.org Cc: Jan Kara jack@suse.cz Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/eventpoll.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)

--- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -772,7 +772,7 @@ static bool __ep_remove(struct eventpoll call_rcu(&epi->rcu, epi_rcu_free);

percpu_counter_dec(&ep->user->epoll_watches); - return ep_refcount_dec_and_test(ep); + return true; }

/* @@ -780,14 +780,14 @@ static bool __ep_remove(struct eventpoll */ static void ep_remove_safe(struct eventpoll *ep, struct epitem *epi) { - WARN_ON_ONCE(__ep_remove(ep, epi, false)); + if (__ep_remove(ep, epi, false)) + WARN_ON_ONCE(ep_refcount_dec_and_test(ep)); }

static void ep_clear_and_put(struct eventpoll *ep) { struct rb_node *rbp, *next; struct epitem *epi; - bool dispose;

/* We need to release all tasks waiting for these file */ if (waitqueue_active(&ep->poll_wait)) @@ -820,10 +820,8 @@ static void ep_clear_and_put(struct even cond_resched(); }

- dispose = ep_refcount_dec_and_test(ep); mutex_unlock(&ep->mtx); - - if (dispose) + if (ep_refcount_dec_and_test(ep)) ep_free(ep); }

@@ -1003,7 +1001,7 @@ again: dispose = __ep_remove(ep, epi, true); mutex_unlock(&ep->mtx);

- if (dispose) + if (dispose && ep_refcount_dec_and_test(ep)) ep_free(ep); goto again; }