6.17-stable review patch. If anyone has any objections, please let me know.
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From: Fernando Fernandez Mancera fmancera@suse.de
[ Upstream commit c7fbb8218b4ad35fec0bd2256d2b9c8d60331f33 ]
Since commit 0c17270f9b92 ("net: sysfs: Implement is_visible for phys_(port_id, port_name, switch_id)"), __dev_change_net_namespace() can hit WARN_ON() when trying to change owner of a file that isn't visible. See the trace below:
WARNING: CPU: 6 PID: 2938 at net/core/dev.c:12410 __dev_change_net_namespace+0xb89/0xc30 CPU: 6 UID: 0 PID: 2938 Comm: incusd Not tainted 6.17.1-1-mainline #1 PREEMPT(full) 4b783b4a638669fb644857f484487d17cb45ed1f Hardware name: Framework Laptop 13 (AMD Ryzen 7040Series)/FRANMDCP07, BIOS 03.07 02/19/2025 RIP: 0010:__dev_change_net_namespace+0xb89/0xc30 [...] Call Trace: <TASK> ? if6_seq_show+0x30/0x50 do_setlink.isra.0+0xc7/0x1270 ? __nla_validate_parse+0x5c/0xcc0 ? security_capable+0x94/0x1a0 rtnl_newlink+0x858/0xc20 ? update_curr+0x8e/0x1c0 ? update_entity_lag+0x71/0x80 ? sched_balance_newidle+0x358/0x450 ? psi_task_switch+0x113/0x2a0 ? __pfx_rtnl_newlink+0x10/0x10 rtnetlink_rcv_msg+0x346/0x3e0 ? sched_clock+0x10/0x30 ? __pfx_rtnetlink_rcv_msg+0x10/0x10 netlink_rcv_skb+0x59/0x110 netlink_unicast+0x285/0x3c0 ? __alloc_skb+0xdb/0x1a0 netlink_sendmsg+0x20d/0x430 ____sys_sendmsg+0x39f/0x3d0 ? import_iovec+0x2f/0x40 ___sys_sendmsg+0x99/0xe0 __sys_sendmsg+0x8a/0xf0 do_syscall_64+0x81/0x970 ? __sys_bind+0xe3/0x110 ? syscall_exit_work+0x143/0x1b0 ? do_syscall_64+0x244/0x970 ? sock_alloc_file+0x63/0xc0 ? syscall_exit_work+0x143/0x1b0 ? do_syscall_64+0x244/0x970 ? alloc_fd+0x12e/0x190 ? put_unused_fd+0x2a/0x70 ? do_sys_openat2+0xa2/0xe0 ? syscall_exit_work+0x143/0x1b0 ? do_syscall_64+0x244/0x970 ? exc_page_fault+0x7e/0x1a0 entry_SYSCALL_64_after_hwframe+0x76/0x7e [...] </TASK>
Fix this by checking is_visible() before trying to touch the attribute.
Fixes: 303a42769c4c ("sysfs: add sysfs_group{s}_change_owner()") Fixes: 0c17270f9b92 ("net: sysfs: Implement is_visible for phys_(port_id, port_name, switch_id)") Reported-by: Cynthia cynthia@kosmx.dev Closes: https://lore.kernel.org/netdev/01070199e22de7f8-28f711ab-d3f1-46d9-b9a0-048a... Signed-off-by: Fernando Fernandez Mancera fmancera@suse.de Reviewed-by: Jakub Kicinski kuba@kernel.org Link: https://lore.kernel.org/r/20251016101456.4087-1-fmancera@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/sysfs/group.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-)
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index 2d78e94072a0d..e142bac4f9f80 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -498,17 +498,26 @@ int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, } EXPORT_SYMBOL_GPL(compat_only_sysfs_link_entry_to_kobj);
-static int sysfs_group_attrs_change_owner(struct kernfs_node *grp_kn, +static int sysfs_group_attrs_change_owner(struct kobject *kobj, + struct kernfs_node *grp_kn, const struct attribute_group *grp, struct iattr *newattrs) { struct kernfs_node *kn; - int error; + int error, i; + umode_t mode;
if (grp->attrs) { struct attribute *const *attr;
- for (attr = grp->attrs; *attr; attr++) { + for (i = 0, attr = grp->attrs; *attr; i++, attr++) { + if (grp->is_visible) { + mode = grp->is_visible(kobj, *attr, i); + if (mode & SYSFS_GROUP_INVISIBLE) + break; + if (!mode) + continue; + } kn = kernfs_find_and_get(grp_kn, (*attr)->name); if (!kn) return -ENOENT; @@ -523,7 +532,14 @@ static int sysfs_group_attrs_change_owner(struct kernfs_node *grp_kn, if (grp->bin_attrs) { const struct bin_attribute *const *bin_attr;
- for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) { + for (i = 0, bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) { + if (grp->is_bin_visible) { + mode = grp->is_bin_visible(kobj, *bin_attr, i); + if (mode & SYSFS_GROUP_INVISIBLE) + break; + if (!mode) + continue; + } kn = kernfs_find_and_get(grp_kn, (*bin_attr)->attr.name); if (!kn) return -ENOENT; @@ -573,7 +589,7 @@ int sysfs_group_change_owner(struct kobject *kobj,
error = kernfs_setattr(grp_kn, &newattrs); if (!error) - error = sysfs_group_attrs_change_owner(grp_kn, grp, &newattrs); + error = sysfs_group_attrs_change_owner(kobj, grp_kn, grp, &newattrs);
kernfs_put(grp_kn);