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| author | Christian Brauner <brauner@kernel.org> | 2025-04-07 11:54:15 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-04-07 16:18:46 +0200 |
| commit | cfd86ef7e8e7b9e015707e46479a6b1de141eed0 (patch) | |
| tree | 85e16b07ef273652843b4dde624d2062f7efb655 /fs/libfs.c | |
| parent | docs: initramfs: update compression and mtime descriptions (diff) | |
| download | linux-cfd86ef7e8e7b9e015707e46479a6b1de141eed0.tar.gz linux-cfd86ef7e8e7b9e015707e46479a6b1de141eed0.zip | |
anon_inode: use a proper mode internally
This allows the VFS to not trip over anonymous inodes and we can add
asserts based on the mode into the vfs. When we report it to userspace
we can simply hide the mode to avoid regressions. I've audited all
direct callers of alloc_anon_inode() and only secretmen overrides i_mode
and i_op inode operations but it already uses a regular file.
Link: https://lore.kernel.org/20250407-work-anon_inode-v1-1-53a44c20d44e@kernel.org
Fixes: af153bb63a336 ("vfs: catch invalid modes in may_open()")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: stable@vger.kernel.org # all LTS kernels
Reported-by: syzbot+5d8e79d323a13aa0b248@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/67ed3fb3.050a0220.14623d.0009.GAE@google.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/libfs.c')
| -rw-r--r-- | fs/libfs.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/libfs.c b/fs/libfs.c index 6393d7c49ee6..e1146620346e 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -1647,7 +1647,13 @@ struct inode *alloc_anon_inode(struct super_block *s) * that it already _is_ on the dirty list. */ inode->i_state = I_DIRTY; - inode->i_mode = S_IRUSR | S_IWUSR; + /* + * Historically anonymous inodes didn't have a type at all and + * userspace has come to rely on this. Internally they're just + * regular files but S_IFREG is masked off when reporting + * information to userspace. + */ + inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR; inode->i_uid = current_fsuid(); inode->i_gid = current_fsgid(); inode->i_flags |= S_PRIVATE; |