The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 8a29c1260e24e7c9c6ab138aa0017558d8b28208 Mon Sep 17 00:00:00 2001

From: Jaegeuk Kim jaegeuk@kernel.org Date: Tue, 24 Apr 2018 21:34:05 -0600 Subject: [PATCH] f2fs: sanity check for total valid node blocks

This patch enhances sanity check for SIT entries.

syzbot hit the following crash on upstream commit 83beed7b2b26f232d782127792dd0cd4362fdc41 (Fri Apr 20 17:56:32 2018 +0000) Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal syzbot dashboard link: https://syzkaller.appspot.com/bug?extid=bf9253040425feb155ad

syzkaller reproducer: https://syzkaller.appspot.com/x/repro.syz?id=5692130282438656 Raw console output: https://syzkaller.appspot.com/x/log.txt?id=5095924598571008 Kernel config: https://syzkaller.appspot.com/x/.config?id=1808800213120130118 compiler: gcc (GCC) 8.0.1 20180413 (experimental)

IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+bf9253040425feb155ad@syzkaller.appspotmail.com It will help syzbot understand when the bug is fixed. See footer for details. If you forward the report, please keep this part and the footer.

F2FS-fs (loop0): invalid crc value F2FS-fs (loop0): Try to recover 1th superblock, ret: 0 F2FS-fs (loop0): Mounted with checkpoint version = d F2FS-fs (loop0): Bitmap was wrongly cleared, blk:9740 ------------[ cut here ]------------ kernel BUG at fs/f2fs/segment.c:1884! invalid opcode: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 4508 Comm: syz-executor0 Not tainted 4.17.0-rc1+ #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:update_sit_entry+0x1215/0x1590 fs/f2fs/segment.c:1882 RSP: 0018:ffff8801af526708 EFLAGS: 00010282 RAX: ffffed0035ea4cc0 RBX: ffff8801ad454f90 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff82eeb87e RDI: ffffed0035ea4cb6 RBP: ffff8801af526760 R08: ffff8801ad4a2480 R09: ffffed003b5e4f90 R10: ffffed003b5e4f90 R11: ffff8801daf27c87 R12: ffff8801adb8d380 R13: 0000000000000001 R14: 0000000000000008 R15: 00000000ffffffff FS: 00000000014af940(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f06bc223000 CR3: 00000001adb02000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: allocate_data_block+0x66f/0x2050 fs/f2fs/segment.c:2663 do_write_page+0x105/0x1b0 fs/f2fs/segment.c:2727 write_node_page+0x129/0x350 fs/f2fs/segment.c:2770 __write_node_page+0x7da/0x1370 fs/f2fs/node.c:1398 sync_node_pages+0x18cf/0x1eb0 fs/f2fs/node.c:1652 block_operations+0x429/0xa60 fs/f2fs/checkpoint.c:1088 write_checkpoint+0x3ba/0x5380 fs/f2fs/checkpoint.c:1405 f2fs_sync_fs+0x2fb/0x6a0 fs/f2fs/super.c:1077 __sync_filesystem fs/sync.c:39 [inline] sync_filesystem+0x265/0x310 fs/sync.c:67 generic_shutdown_super+0xd7/0x520 fs/super.c:429 kill_block_super+0xa4/0x100 fs/super.c:1191 kill_f2fs_super+0x9f/0xd0 fs/f2fs/super.c:3030 deactivate_locked_super+0x97/0x100 fs/super.c:316 deactivate_super+0x188/0x1b0 fs/super.c:347 cleanup_mnt+0xbf/0x160 fs/namespace.c:1174 __cleanup_mnt+0x16/0x20 fs/namespace.c:1181 task_work_run+0x1e4/0x290 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457d97 RSP: 002b:00007ffd46f9c8e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000457d97 RDX: 00000000014b09a3 RSI: 0000000000000002 RDI: 00007ffd46f9da50 RBP: 00007ffd46f9da50 R08: 0000000000000000 R09: 0000000000000009 R10: 0000000000000005 R11: 0000000000000246 R12: 00000000014b0940 R13: 0000000000000000 R14: 0000000000000002 R15: 000000000000658e RIP: update_sit_entry+0x1215/0x1590 fs/f2fs/segment.c:1882 RSP: ffff8801af526708 ---[ end trace f498328bb02610a2 ]---

Reported-and-tested-by: syzbot+bf9253040425feb155ad@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+7d6d31d3bc702f566ce3@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+0a725420475916460f12@syzkaller.appspotmail.com Reviewed-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 3ba8a4a768c9..1576b9d9a172 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -3631,6 +3631,7 @@ static int build_sit_entries(struct f2fs_sb_info *sbi) unsigned int i, start, end; unsigned int readed, start_blk = 0; int err = 0; + block_t total_node_blocks = 0;

do { readed = ra_meta_pages(sbi, start_blk, BIO_MAX_PAGES, @@ -3653,6 +3654,8 @@ static int build_sit_entries(struct f2fs_sb_info *sbi) if (err) return err; seg_info_from_raw_sit(se, &sit); + if (IS_NODESEG(se->type)) + total_node_blocks += se->valid_blocks;

/* build discard map only one time */ if (f2fs_discard_en(sbi)) { @@ -3694,11 +3697,15 @@ static int build_sit_entries(struct f2fs_sb_info *sbi) sit = sit_in_journal(journal, i);

old_valid_blocks = se->valid_blocks; + if (IS_NODESEG(se->type)) + total_node_blocks -= old_valid_blocks;

err = check_block_count(sbi, start, &sit); if (err) break; seg_info_from_raw_sit(se, &sit); + if (IS_NODESEG(se->type)) + total_node_blocks += se->valid_blocks;

if (f2fs_discard_en(sbi)) { if (is_set_ckpt_flags(sbi, CP_TRIMMED_FLAG)) { @@ -3717,6 +3724,15 @@ static int build_sit_entries(struct f2fs_sb_info *sbi) se->valid_blocks - old_valid_blocks; } up_read(&curseg->journal_rwsem); + + if (!err && total_node_blocks != valid_node_count(sbi)) { + f2fs_msg(sbi->sb, KERN_ERR, + "SIT is corrupted node# %u vs %u", + total_node_blocks, valid_node_count(sbi)); + set_sbi_flag(sbi, SBI_NEED_FSCK); + err = -EINVAL; + } + return err; }