The patch titled Subject: memfd: check for non-NULL file_seals in memfd_create() syscall has been added to the -mm mm-hotfixes-unstable branch. Its filename is memfd-check-for-non-null-file_seals-in-memfd_create-syscall.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------ From: Roberto Sassu roberto.sassu@huawei.com Subject: memfd: check for non-NULL file_seals in memfd_create() syscall Date: Wed, 7 Jun 2023 15:24:27 +0200

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 is when CONFIG_SHMEM=n.

Link: https://lkml.kernel.org/r/20230607132427.2867435-1-roberto.sassu@huaweicloud... 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 ---

mm/memfd.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)

--- a/mm/memfd.c~memfd-check-for-non-null-file_seals-in-memfd_create-syscall +++ a/mm/memfd.c @@ -371,12 +371,15 @@ SYSCALL_DEFINE2(memfd_create,

inode->i_mode &= ~0111; file_seals = memfd_file_seals_ptr(file); - *file_seals &= ~F_SEAL_SEAL; - *file_seals |= F_SEAL_EXEC; + if (file_seals) { + *file_seals &= ~F_SEAL_SEAL; + *file_seals |= F_SEAL_EXEC; + } } else if (flags & MFD_ALLOW_SEALING) { /* MFD_EXEC and MFD_ALLOW_SEALING are set */ file_seals = memfd_file_seals_ptr(file); - *file_seals &= ~F_SEAL_SEAL; + if (file_seals) + *file_seals &= ~F_SEAL_SEAL; }

fd_install(fd, file); _

Patches currently in -mm which might be from roberto.sassu@huawei.com are

memfd-check-for-non-null-file_seals-in-memfd_create-syscall.patch