iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

memfd: check for non-NULL file_seals in memfd_create() syscall

Browse Source 
[ Upstream commit 935d44acf621aa0688fef8312dec3e5940f38f4e ]

Ensure that file_seals is non-NULL before using it in the memfd_create()
syscall.  One situation in which memfd_file_seals_ptr() could return a
NULL pointer when CONFIG_SHMEM=n, oopsing the kernel.

Link: https://lkml.kernel.org/r/20230607132427.2867435-1-roberto.sassu@huaweicloud.com
Fixes: 47b9012ecdc7 ("shmem: add sealing support to hugetlb-backed memfd")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Cc: Marc-Andr Lureau <marcandre.lureau@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Roberto Sassu 2023-06-07 15:24:27 +02:00 committed by Greg Kroah-Hartman
parent 1ac6e9ee84
commit 051d642133
1 changed files with 2 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
mm/memfd.c
View File

@ -330,7 +330,8 @@ SYSCALL_DEFINE2(memfd_create,
if (flags & MFD_ALLOW_SEALING) {
file_seals = memfd_file_seals_ptr(file);
*file_seals &= ~F_SEAL_SEAL;
if (file_seals)
*file_seals &= ~F_SEAL_SEAL;
}
fd_install(fd, file);