This is a note to let you know that I've just added the patch titled ext4: Fix BUG_ON in ext4_bread when write quota data to the 5.16-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: ext4-fix-bug_on-in-ext4_bread-when-write-quota-data.patch and it can be found in the queue-5.16 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 380a0091cab482489e9b19e07f2a166ad2b76d5c Mon Sep 17 00:00:00 2001 From: Ye Bin <yebin10@xxxxxxxxxx> Date: Thu, 23 Dec 2021 09:55:06 +0800 Subject: ext4: Fix BUG_ON in ext4_bread when write quota data From: Ye Bin <yebin10@xxxxxxxxxx> commit 380a0091cab482489e9b19e07f2a166ad2b76d5c upstream. We got issue as follows when run syzkaller: [ 167.936972] EXT4-fs error (device loop0): __ext4_remount:6314: comm rep: Abort forced by user [ 167.938306] EXT4-fs (loop0): Remounting filesystem read-only [ 167.981637] Assertion failure in ext4_getblk() at fs/ext4/inode.c:847: '(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY) || handle != NULL || create == 0' [ 167.983601] ------------[ cut here ]------------ [ 167.984245] kernel BUG at fs/ext4/inode.c:847! [ 167.984882] invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI [ 167.985624] CPU: 7 PID: 2290 Comm: rep Tainted: G B 5.16.0-rc5-next-20211217+ #123 [ 167.986823] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 [ 167.988590] RIP: 0010:ext4_getblk+0x17e/0x504 [ 167.989189] Code: c6 01 74 28 49 c7 c0 a0 a3 5c 9b b9 4f 03 00 00 48 c7 c2 80 9c 5c 9b 48 c7 c6 40 b6 5c 9b 48 c7 c7 20 a4 5c 9b e8 77 e3 fd ff <0f> 0b 8b 04 244 [ 167.991679] RSP: 0018:ffff8881736f7398 EFLAGS: 00010282 [ 167.992385] RAX: 0000000000000094 RBX: 1ffff1102e6dee75 RCX: 0000000000000000 [ 167.993337] RDX: 0000000000000001 RSI: ffffffff9b6e29e0 RDI: ffffed102e6dee66 [ 167.994292] RBP: ffff88816a076210 R08: 0000000000000094 R09: ffffed107363fa09 [ 167.995252] R10: ffff88839b1fd047 R11: ffffed107363fa08 R12: ffff88816a0761e8 [ 167.996205] R13: 0000000000000000 R14: 0000000000000021 R15: 0000000000000001 [ 167.997158] FS: 00007f6a1428c740(0000) GS:ffff88839b000000(0000) knlGS:0000000000000000 [ 167.998238] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 167.999025] CR2: 00007f6a140716c8 CR3: 0000000133216000 CR4: 00000000000006e0 [ 167.999987] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 168.000944] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 168.001899] Call Trace: [ 168.002235] <TASK> [ 168.007167] ext4_bread+0xd/0x53 [ 168.007612] ext4_quota_write+0x20c/0x5c0 [ 168.010457] write_blk+0x100/0x220 [ 168.010944] remove_free_dqentry+0x1c6/0x440 [ 168.011525] free_dqentry.isra.0+0x565/0x830 [ 168.012133] remove_tree+0x318/0x6d0 [ 168.014744] remove_tree+0x1eb/0x6d0 [ 168.017346] remove_tree+0x1eb/0x6d0 [ 168.019969] remove_tree+0x1eb/0x6d0 [ 168.022128] qtree_release_dquot+0x291/0x340 [ 168.023297] v2_release_dquot+0xce/0x120 [ 168.023847] dquot_release+0x197/0x3e0 [ 168.024358] ext4_release_dquot+0x22a/0x2d0 [ 168.024932] dqput.part.0+0x1c9/0x900 [ 168.025430] __dquot_drop+0x120/0x190 [ 168.025942] ext4_clear_inode+0x86/0x220 [ 168.026472] ext4_evict_inode+0x9e8/0xa22 [ 168.028200] evict+0x29e/0x4f0 [ 168.028625] dispose_list+0x102/0x1f0 [ 168.029148] evict_inodes+0x2c1/0x3e0 [ 168.030188] generic_shutdown_super+0xa4/0x3b0 [ 168.030817] kill_block_super+0x95/0xd0 [ 168.031360] deactivate_locked_super+0x85/0xd0 [ 168.031977] cleanup_mnt+0x2bc/0x480 [ 168.033062] task_work_run+0xd1/0x170 [ 168.033565] do_exit+0xa4f/0x2b50 [ 168.037155] do_group_exit+0xef/0x2d0 [ 168.037666] __x64_sys_exit_group+0x3a/0x50 [ 168.038237] do_syscall_64+0x3b/0x90 [ 168.038751] entry_SYSCALL_64_after_hwframe+0x44/0xae In order to reproduce this problem, the following conditions need to be met: 1. Ext4 filesystem with no journal; 2. Filesystem image with incorrect quota data; 3. Abort filesystem forced by user; 4. umount filesystem; As in ext4_quota_write: ... if (EXT4_SB(sb)->s_journal && !handle) { ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)" " cancelled because transaction is not started", (unsigned long long)off, (unsigned long long)len); return -EIO; } ... We only check handle if NULL when filesystem has journal. There is need check handle if NULL even when filesystem has no journal. Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> Link: https://lore.kernel.org/r/20211223015506.297766-1-yebin10@xxxxxxxxxx Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Cc: stable@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -6479,7 +6479,7 @@ static ssize_t ext4_quota_write(struct s struct buffer_head *bh; handle_t *handle = journal_current_handle(); - if (EXT4_SB(sb)->s_journal && !handle) { + if (!handle) { ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)" " cancelled because transaction is not started", (unsigned long long)off, (unsigned long long)len); Patches currently in stable-queue which might be from yebin10@xxxxxxxxxx are queue-5.16/ext4-fix-null-ptr-deref-in-__ext4_journal_ensure_credits.patch queue-5.16/ext4-fix-bug_on-in-ext4_bread-when-write-quota-data.patch