Vulnerability in Linux

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: smb: client: use finish_no_open() for non-regular inodes An O_CREAT open can find an existing symlink or another non-regular inode. cifs_atomic_open() calls finish_open() on it and attaches a cifsFileInfo. Symlink inodes have no CIFS release operation, so the dentry reference held by cifsFileInfo is leaked. FMODE_OPENED also prevents the VFS from following the symlink. Track whether cifs_do_create() returned an open server handle. For non-regular inodes, close the handle if present, remove the pending open, and call finish_no_open() so the VFS can continue the lookup. Do not set FMODE_CREATED unless a regular file was opened. For O_NOFOLLOW with __O_REGULAR, return -ELOOP before the VFS's -EFTYPE check. Defer closing a legacy POSIX handle on a non-regular inode until after inode lookup. This avoids closing it again if lookup fails.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• git.kernel.org/stable/c/045532f920d86dd76600b635f9756e5fd671ddfc
• git.kernel.org/stable/c/3c07deb26273155c180aedfd9041ab58015d2521
• git.kernel.org/stable/c/70a7918fda54a06d836acc91eb9a3c7e860fe0a0
• git.kernel.org/stable/c/e66cf1625ec4a3fe68346119f371def713fd0a4d
• git.kernel.org/stable/c/ed03d547598c92a036f20e89156540995cac889a