The quilt patch titled Subject: fat: fix uninitialized field in nostale filehandles has been removed from the -mm tree. Its filename was fat-fix-uninitialized-field-in-nostale-filehandles.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Jan Kara <jack@xxxxxxx> Subject: fat: fix uninitialized field in nostale filehandles Date: Mon, 5 Feb 2024 13:26:26 +0100 When fat_encode_fh_nostale() encodes file handle without a parent it stores only first 10 bytes of the file handle. However the length of the file handle must be a multiple of 4 so the file handle is actually 12 bytes long and the last two bytes remain uninitialized. This is not great at we potentially leak uninitialized information with the handle to userspace. Properly initialize the full handle length. Link: https://lkml.kernel.org/r/20240205122626.13701-1-jack@xxxxxxx Reported-by: syzbot+3ce5dea5b1539ff36769@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: ea3983ace6b7 ("fat: restructure export_operations") Signed-off-by: Jan Kara <jack@xxxxxxx> Acked-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> Cc: Amir Goldstein <amir73il@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/fat/nfs.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/fat/nfs.c~fat-fix-uninitialized-field-in-nostale-filehandles +++ a/fs/fat/nfs.c @@ -130,6 +130,12 @@ fat_encode_fh_nostale(struct inode *inod fid->parent_i_gen = parent->i_generation; type = FILEID_FAT_WITH_PARENT; *lenp = FAT_FID_SIZE_WITH_PARENT; + } else { + /* + * We need to initialize this field because the fh is actually + * 12 bytes long + */ + fid->parent_i_pos_hi = 0; } return type; _ Patches currently in -mm which might be from jack@xxxxxxx are shmem-properly-report-quota-mount-options.patch