The patch titled Subject: Squashfs: fix variable overflow triggered by sysbot has been added to the -mm mm-nonmm-unstable branch. Its filename is squashfs-fix-variable-overflow-triggered-by-sysbot.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/squashfs-fix-variable-overflow-triggered-by-sysbot.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Phillip Lougher <phillip@xxxxxxxxxxxxxxx> Subject: Squashfs: fix variable overflow triggered by sysbot Date: Mon, 13 Nov 2023 16:09:01 +0000 Sysbot reports a slab out of bounds write in squashfs_readahead(). This is ultimately caused by a file reporting an (infeasibly) large file size (1407374883553280 bytes) with the minimum block size of 4K. This causes variable overflow. Link: https://lkml.kernel.org/r/20231113160901.6444-1-phillip@xxxxxxxxxxxxxxx Signed-off-by: Phillip Lougher <phillip@xxxxxxxxxxxxxxx> Reported-by: syzbot+604424eb051c2f696163@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://lore.kernel.org/all/000000000000b1fda20609ede0d1@xxxxxxxxxx/ Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/squashfs/file.c | 3 ++- fs/squashfs/file_direct.c | 6 +++--- 2 files changed, 5 insertions(+), 4 deletions(-) --- a/fs/squashfs/file.c~squashfs-fix-variable-overflow-triggered-by-sysbot +++ a/fs/squashfs/file.c @@ -544,7 +544,8 @@ static void squashfs_readahead(struct re struct squashfs_page_actor *actor; unsigned int nr_pages = 0; struct page **pages; - int i, file_end = i_size_read(inode) >> msblk->block_log; + int i; + loff_t file_end = i_size_read(inode) >> msblk->block_log; unsigned int max_pages = 1UL << shift; readahead_expand(ractl, start, (len | mask) + 1); --- a/fs/squashfs/file_direct.c~squashfs-fix-variable-overflow-triggered-by-sysbot +++ a/fs/squashfs/file_direct.c @@ -26,10 +26,10 @@ int squashfs_readpage_block(struct page struct inode *inode = target_page->mapping->host; struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; - int file_end = (i_size_read(inode) - 1) >> PAGE_SHIFT; + loff_t file_end = (i_size_read(inode) - 1) >> PAGE_SHIFT; int mask = (1 << (msblk->block_log - PAGE_SHIFT)) - 1; - int start_index = target_page->index & ~mask; - int end_index = start_index | mask; + loff_t start_index = target_page->index & ~mask; + loff_t end_index = start_index | mask; int i, n, pages, bytes, res = -ENOMEM; struct page **page; struct squashfs_page_actor *actor; _ Patches currently in -mm which might be from phillip@xxxxxxxxxxxxxxx are squashfs-fix-variable-overflow-triggered-by-sysbot.patch