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authorLinus Torvalds <torvalds@linux-foundation.org>2023-08-28 20:17:14 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-08-28 20:17:14 +0300
commitde16588a7737b12e63ec646d72b45befb2b1f8f7 (patch)
tree719d3271039eca6ca315201e0cd882658133a2f8 /fs/attr.c
parentecd7db20474c3859d4d01f34aaabf41bd28c7d84 (diff)
parente6fa4c728fb671765291cca3a905986612c06b6e (diff)
downloadlinux-de16588a7737b12e63ec646d72b45befb2b1f8f7.tar.xz
Merge tag 'v6.6-vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner: "This contains the usual miscellaneous features, cleanups, and fixes for vfs and individual filesystems. Features: - Block mode changes on symlinks and rectify our broken semantics - Report file modifications via fsnotify() for splice - Allow specifying an explicit timeout for the "rootwait" kernel command line option. This allows to timeout and reboot instead of always waiting indefinitely for the root device to show up - Use synchronous fput for the close system call Cleanups: - Get rid of open-coded lockdep workarounds for async io submitters and replace it all with a single consolidated helper - Simplify epoll allocation helper - Convert simple_write_begin and simple_write_end to use a folio - Convert page_cache_pipe_buf_confirm() to use a folio - Simplify __range_close to avoid pointless locking - Disable per-cpu buffer head cache for isolated cpus - Port ecryptfs to kmap_local_page() api - Remove redundant initialization of pointer buf in pipe code - Unexport the d_genocide() function which is only used within core vfs - Replace printk(KERN_ERR) and WARN_ON() with WARN() Fixes: - Fix various kernel-doc issues - Fix refcount underflow for eventfds when used as EFD_SEMAPHORE - Fix a mainly theoretical issue in devpts - Check the return value of __getblk() in reiserfs - Fix a racy assert in i_readcount_dec - Fix integer conversion issues in various functions - Fix LSM security context handling during automounts that prevented NFS superblock sharing" * tag 'v6.6-vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (39 commits) cachefiles: use kiocb_{start,end}_write() helpers ovl: use kiocb_{start,end}_write() helpers aio: use kiocb_{start,end}_write() helpers io_uring: use kiocb_{start,end}_write() helpers fs: create kiocb_{start,end}_write() helpers fs: add kerneldoc to file_{start,end}_write() helpers io_uring: rename kiocb_end_write() local helper splice: Convert page_cache_pipe_buf_confirm() to use a folio libfs: Convert simple_write_begin and simple_write_end to use a folio fs/dcache: Replace printk and WARN_ON by WARN fs/pipe: remove redundant initialization of pointer buf fs: Fix kernel-doc warnings devpts: Fix kernel-doc warnings doc: idmappings: fix an error and rephrase a paragraph init: Add support for rootwait timeout parameter vfs: fix up the assert in i_readcount_dec fs: Fix one kernel-doc comment docs: filesystems: idmappings: clarify from where idmappings are taken fs/buffer.c: disable per-CPU buffer_head cache for isolated CPUs vfs, security: Fix automount superblock LSM init problem, preventing NFS sb sharing ...
Diffstat (limited to 'fs/attr.c')
-rw-r--r--fs/attr.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/fs/attr.c b/fs/attr.c
index 599f6d14c0ed..a8ae5f6d9b16 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -394,9 +394,25 @@ int notify_change(struct mnt_idmap *idmap, struct dentry *dentry,
return error;
if ((ia_valid & ATTR_MODE)) {
- umode_t amode = attr->ia_mode;
+ /*
+ * Don't allow changing the mode of symlinks:
+ *
+ * (1) The vfs doesn't take the mode of symlinks into account
+ * during permission checking.
+ * (2) This has never worked correctly. Most major filesystems
+ * did return EOPNOTSUPP due to interactions with POSIX ACLs
+ * but did still updated the mode of the symlink.
+ * This inconsistency led system call wrapper providers such
+ * as libc to block changing the mode of symlinks with
+ * EOPNOTSUPP already.
+ * (3) To even do this in the first place one would have to use
+ * specific file descriptors and quite some effort.
+ */
+ if (S_ISLNK(inode->i_mode))
+ return -EOPNOTSUPP;
+
/* Flag setting protected by i_mutex */
- if (is_sxid(amode))
+ if (is_sxid(attr->ia_mode))
inode->i_flags &= ~S_NOSEC;
}