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
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------------------------------------------------------
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
