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filelock: Correct the filelock owner in fcntl_setlk/fcntl_setlk64 

BugLink: https://bugs.launchpad.net/bugs/2080595

The locks_remove_posix() function in fcntl_setlk/fcntl_setlk64 is designed
to reliably remove locks when an fcntl/close race is detected. However, it
was passing in the wrong filelock owner, it looks like a mistake and
resulting in a failure to remove locks. More critically, if the lock
removal fails, it could lead to a uaf issue while traversing the locks.

This problem occurs only in the 4.19/5.4 stable version.

Fixes: 4c43ad4ab416 ("filelock: Fix fcntl/close race recovery compat path")
Fixes: dc2ce1dfceaa ("filelock: Remove locks reliably when fcntl/close race is detected")
Cc: stable@vger.kernel.org
Signed-off-by: Long Li <leo.lilong@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
This commit is contained in:
Long Li 2024-08-16 13:06:27 +08:00 committed by Stefan Bader
parent 72268f593c
commit ee9bc21135
1 changed files with 2 additions and 2 deletions

4
fs/locks.c
View File

@ -2542,7 +2542,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
f = fcheck(fd);
spin_unlock(&current->files->file_lock);
if (f != filp) {
locks_remove_posix(filp, &current->files);
locks_remove_posix(filp, current->files);
error = -EBADF;
}
}
@ -2672,7 +2672,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd,
f = fcheck(fd);
spin_unlock(&current->files->file_lock);
if (f != filp) {
locks_remove_posix(filp, &current->files);
locks_remove_posix(filp, current->files);
error = -EBADF;
}
}