kernel/git/stable/linux.git/fs/f2fs/acl.c, branch linux-7.2.y

f2fs: validate ACL entry sizes in f2fs_acl_from_disk()

2026-06-22T19:52:37+00:00

f2fs_acl_count() only validates the aggregate ACL xattr length. A malformed ACL can still place ACL_USER or ACL_GROUP in a slot that only contains struct f2fs_acl_entry_short bytes, and f2fs_acl_from_disk() then reads entry->e_id before verifying that a full entry fits. Require a short entry before reading e_tag and e_perm, and require a full entry before reading e_id for ACL_USER and ACL_GROUP. Return -EFSCORRUPTED from these new truncated-entry checks, while keeping the pre-existing -EINVAL paths unchanged. Validation reproduced this kernel report: KASAN slab-out-of-bounds in __f2fs_get_acl+0x6fb/0x7e0 RIP: 0033:0x7f4b835ea7aa The buggy address belongs to the object at ffff888114589960 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes to the right of allocated 8-byte region [ffff888114589960, ffff888114589968) Read of size 4 Call trace: dump_stack_lvl+0x66/0xa0 (?:?) print_report+0xce/0x630 (?:?) __f2fs_get_acl+0x6fb/0x7e0 (fs/f2fs/acl.c:169) srso_alias_return_thunk+0x5/0xfbef5 (?:?) __virt_addr_valid+0x224/0x430 (?:?) kasan_report+0xe0/0x110 (?:?) __f2fs_get_acl+0x5/0x7e0 (fs/f2fs/acl.c:169) __get_acl+0x281/0x380 (?:?) vfs_get_acl+0x10b/0x190 (?:?) do_get_acl+0x2a/0x410 (?:?) do_get_acl+0x9/0x410 (?:?) do_getxattr+0xe8/0x260 (?:?) filename_getxattr+0xd1/0x140 (?:?) do_getname+0x2d/0x2d0 (?:?) path_getxattrat+0x16c/0x200 (?:?) lock_release+0xc8/0x290 (?:?) cgroup_update_frozen+0x9d/0x320 (?:?) lockdep_hardirqs_on_prepare+0xea/0x1a0 (?:?) trace_hardirqs_on+0x1a/0x170 (?:?) _raw_spin_unlock_irq+0x28/0x50 (?:?) do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?) Cc: stable@kernel.org Fixes: af48b85b8cd3 ("f2fs: add xattr and acl functionalities") Assisted-by: Codex:gpt-5.5 Signed-off-by: Zhang Cen Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

fs: inline current_umask() and move it to fs_struct.h

2025-11-05T21:51:23+00:00

There is no good reason to have this as a func call, other than avoiding the churn of adding fs_struct.h as needed. Signed-off-by: Mateusz Guzik Link: https://patch.msgid.link/20251104170448.630414-1-mjguzik@gmail.com Signed-off-by: Christian Brauner

f2fs: Pass a folio to f2fs_getxattr()

2025-04-28T15:26:42+00:00

The one caller of __f2fs_get_acl() which passes a non-NULL page already has a folio, so pass it in, then into f2fs_getxattr(), which lets us pass it to lookup_all_xattrs(). Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: Pass a folio to f2fs_setxattr()

2025-04-28T15:26:41+00:00

Also convert f2fs_initxattrs() to take a folio. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: Pass folios to f2fs_init_acl()

2025-04-28T15:26:41+00:00

The one caller already has folios, so pass them in, and further pass them to __f2fs_set_acl() and f2fs_acl_create(). There should be no change to the generated code for this commit. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: Use struct_size() to improve f2fs_acl_clone()

2024-10-14T20:04:57+00:00

Use struct_size() to calculate the number of bytes to allocate for a cloned acl. Signed-off-by: Thorsten Blum Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: Use in_group_or_capable() helper

2024-06-25T09:15:48+00:00

Use the in_group_or_capable() helper function to simplify the code. Signed-off-by: Youling Tang Link: https://lore.kernel.org/r/20240620032335.147136-2-youling.tang@linux.dev Signed-off-by: Christian Brauner

fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap

2023-01-19T08:24:29+00:00

Convert to struct mnt_idmap. Remove legacy file_mnt_user_ns() and mnt_user_ns(). Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner (Microsoft)

fs: port privilege checking helpers to mnt_idmap

2023-01-19T08:24:29+00:00

Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner (Microsoft)

fs: port ->set_acl() to pass mnt_idmap

2023-01-19T08:24:27+00:00