From: Ye Bin <yebin10@huawei.com> mainline inclusion from mainline-v5.16 commit 39fbef4b0f77f9c89c8f014749ca533643a37c9f category: bugfix bugzilla: 182871 CVE: NA ----------------------------------------------- The following kernel crash can be triggered: [ 89.266592] ------------[ cut here ]------------ [ 89.267427] kernel BUG at fs/buffer.c:3020! [ 89.268264] invalid opcode: 0000 [#1] SMP KASAN PTI [ 89.269116] CPU: 7 PID: 1750 Comm: kmmpd-loop0 Not tainted 5.10.0-862.14.0.6.x86_64-08610-gc932cda3cef4-dirty #20 [ 89.273169] RIP: 0010:submit_bh_wbc.isra.0+0x538/0x6d0 [ 89.277157] RSP: 0018:ffff888105ddfd08 EFLAGS: 00010246 [ 89.278093] RAX: 0000000000000005 RBX: ffff888124231498 RCX: ffffffffb2772612 [ 89.279332] RDX: 1ffff11024846293 RSI: 0000000000000008 RDI: ffff888124231498 [ 89.280591] RBP: ffff8881248cc000 R08: 0000000000000001 R09: ffffed1024846294 [ 89.281851] R10: ffff88812423149f R11: ffffed1024846293 R12: 0000000000003800 [ 89.283095] R13: 0000000000000001 R14: 0000000000000000 R15: ffff8881161f7000 [ 89.284342] FS: 0000000000000000(0000) GS:ffff88839b5c0000(0000) knlGS:0000000000000000 [ 89.285711] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 89.286701] CR2: 00007f166ebc01a0 CR3: 0000000435c0e000 CR4: 00000000000006e0 [ 89.287919] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 89.289138] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 89.290368] Call Trace: [ 89.290842] write_mmp_block+0x2ca/0x510 [ 89.292218] kmmpd+0x433/0x9a0 [ 89.294902] kthread+0x2dd/0x3e0 [ 89.296268] ret_from_fork+0x22/0x30 [ 89.296906] Modules linked in: by running the following commands: 1. mkfs.ext4 -O mmp /dev/sda -b 1024 2. mount /dev/sda /home/test 3. echo "/dev/sda" > /sys/power/resume That happens because swsusp_check() calls set_blocksize() on the target partition which confuses the file system: Thread1 Thread2 mount /dev/sda /home/test get s_mmp_bh --> has mapped flag start kmmpd thread echo "/dev/sda" > /sys/power/resume resume_store software_resume swsusp_check set_blocksize truncate_inode_pages_range truncate_cleanup_page block_invalidatepage discard_buffer --> clean mapped flag write_mmp_block submit_bh submit_bh_wbc BUG_ON(!buffer_mapped(bh)) To address this issue, modify swsusp_check() to open the target block device with exclusive access. Signed-off-by: Ye Bin <yebin10@huawei.com> [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ye Bin <yebin10@huawei.com> Reviewed-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- kernel/power/swap.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/power/swap.c b/kernel/power/swap.c index d7f6c1a288d33..4fde37fce4ea4 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -1512,9 +1512,10 @@ int swsusp_read(unsigned int *flags_p) int swsusp_check(void) { int error; + void *holder; hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, - FMODE_READ, NULL); + FMODE_READ | FMODE_EXCL, &holder); if (!IS_ERR(hib_resume_bdev)) { set_blocksize(hib_resume_bdev, PAGE_SIZE); clear_page(swsusp_header); @@ -1536,7 +1537,7 @@ int swsusp_check(void) put: if (error) - blkdev_put(hib_resume_bdev, FMODE_READ); + blkdev_put(hib_resume_bdev, FMODE_READ | FMODE_EXCL); else pr_debug("Image signature found, resuming\n"); } else { -- 2.25.1