The quilt patch titled Subject: squashfs: fix oob in squashfs_readahead has been removed from the -mm tree. Its filename was squashfs-fix-oob-in-squashfs_readahead.patch This patch was dropped because it was nacked ------------------------------------------------------ From: Edward Adam Davis <eadavis@xxxxxx> Subject: squashfs: fix oob in squashfs_readahead Date: Wed, 15 Nov 2023 12:05:35 +0800 [Syz log] SQUASHFS error: Failed to read block 0x6fc: -5 SQUASHFS error: Unable to read metadata cache entry [6fa] SQUASHFS error: Unable to read metadata cache entry [6fa] SQUASHFS error: Unable to read metadata cache entry [6fa] ================================================================== BUG: KASAN: slab-out-of-bounds in __readahead_batch include/linux/pagemap.h:1364 [inline] BUG: KASAN: slab-out-of-bounds in squashfs_readahead+0x9a6/0x20d0 fs/squashfs/file.c:569 Write of size 8 at addr ffff88801e393648 by task syz-executor100/5067 CPU: 1 PID: 5067 Comm: syz-executor100 Not tainted 6.6.0-syzkaller-15156-g13d88ac54ddd #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0x163/0x540 mm/kasan/report.c:475 kasan_report+0x142/0x170 mm/kasan/report.c:588 __readahead_batch include/linux/pagemap.h:1364 [inline] squashfs_readahead+0x9a6/0x20d0 fs/squashfs/file.c:569 read_pages+0x183/0x830 mm/readahead.c:160 page_cache_ra_unbounded+0x68e/0x7c0 mm/readahead.c:269 page_cache_sync_readahead include/linux/pagemap.h:1266 [inline] filemap_get_pages+0x49c/0x2080 mm/filemap.c:2497 filemap_read+0x42b/0x10b0 mm/filemap.c:2593 __kernel_read+0x425/0x8b0 fs/read_write.c:428 integrity_kernel_read+0xb0/0xf0 security/integrity/iint.c:221 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:485 [inline] ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline] ima_calc_file_hash+0xad1/0x1b30 security/integrity/ima/ima_crypto.c:573 ima_collect_measurement+0x554/0xb30 security/integrity/ima/ima_api.c:290 process_measurement+0x1373/0x21c0 security/integrity/ima/ima_main.c:359 ima_file_check+0xf1/0x170 security/integrity/ima/ima_main.c:557 do_open fs/namei.c:3624 [inline] path_openat+0x2893/0x3280 fs/namei.c:3779 [Bug] path_openat() called open_last_lookups() before calling do_open() and open_last_lookups() will eventually call squashfs_read_inode() to set inode->i_size, but before setting i_size, it is necessary to obtain file_size from the disk. However, during the value retrieval process, the length of the value retrieved from the disk was greater than output->length, resulting(-EIO) in the failure of squashfs_read_data(), further leading to i_size has not been initialized, i.e. its value is 0. This resulted in the failure of squashfs_read_data(), where "SQUASHFS error: Failed to read block 0x6fc: -5" was output in the syz log. This also resulted in the failure of squashfs_cache_get(), outputting "SQUASHFS error: Unable to read metadata cache entry [6fa]" in the syz log. [Fix] Before performing a read ahead operation in squashfs_read_folio() and squashfs_readahead(), check if i_size is not 0 before continuing. Optimize the return value of squashfs_read_data() and return -EFBIG when the length is greater than output->length(or (index + length) > msblk->bytes_used). Link: https://lkml.kernel.org/r/tencent_35864B36740976B766CA3CC936A496AA3609@xxxxxx Fixes: f268eedddf35 ("squashfs: extend "page actor" to handle missing pages") Signed-off-by: Edward Adam Davis <eadavis@xxxxxx> Reported-by: syzbot+604424eb051c2f696163@xxxxxxxxxxxxxxxxxxxxxxxxx Tested-by: syzbot+604424eb051c2f696163@xxxxxxxxxxxxxxxxxxxxxxxxx Cc: Phillip Lougher <phillip@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/squashfs/block.c | 2 +- fs/squashfs/file.c | 8 ++++++++ 2 files changed, 9 insertions(+), 1 deletion(-) --- a/fs/squashfs/block.c~squashfs-fix-oob-in-squashfs_readahead +++ a/fs/squashfs/block.c @@ -323,7 +323,7 @@ int squashfs_read_data(struct super_bloc } if (length < 0 || length > output->length || (index + length) > msblk->bytes_used) { - res = -EIO; + res = length < 0 ? -EIO : -EFBIG; goto out; } --- a/fs/squashfs/file.c~squashfs-fix-oob-in-squashfs_readahead +++ a/fs/squashfs/file.c @@ -461,6 +461,11 @@ static int squashfs_read_folio(struct fi TRACE("Entered squashfs_readpage, page index %lx, start block %llx\n", page->index, squashfs_i(inode)->start); + if (!file_end) { + res = -EINVAL; + goto out; + } + if (page->index >= ((i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT)) goto out; @@ -548,6 +553,9 @@ static void squashfs_readahead(struct re loff_t file_end = i_size_read(inode) >> msblk->block_log; unsigned int max_pages = 1UL << shift; + if (!file_end) + return; + readahead_expand(ractl, start, (len | mask) + 1); pages = kmalloc_array(max_pages, sizeof(void *), GFP_KERNEL); _ Patches currently in -mm which might be from eadavis@xxxxxx are