This is a note to let you know that I've just added the patch titled
Squashfs: fix variable overflow triggered by sysbot
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
squashfs-fix-variable-overflow-triggered-by-sysbot.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ef71f9d290154c14c6d34edae7fb3638003fce92
Author: Phillip Lougher <phillip@xxxxxxxxxxxxxxx>
Date: Mon Nov 13 16:09:01 2023 +0000
Squashfs: fix variable overflow triggered by sysbot
[ Upstream commit 12427de9439d68b8e96ba6f50b601ef15f437612 ]
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>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c
index 8ba8c4c507707..e8df6430444b0 100644
--- a/fs/squashfs/file.c
+++ b/fs/squashfs/file.c
@@ -544,7 +544,8 @@ static void squashfs_readahead(struct readahead_control *ractl)
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);
diff --git a/fs/squashfs/file_direct.c b/fs/squashfs/file_direct.c
index f1ccad519e28c..763a3f7a75f6d 100644
--- a/fs/squashfs/file_direct.c
+++ b/fs/squashfs/file_direct.c
@@ -26,10 +26,10 @@ int squashfs_readpage_block(struct page *target_page, u64 block, int bsize,
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;
