[PATCH v2] f2fs: fix to do sanity check with node footer and iblocks

From: Chao Yu
Date: Fri Jul 27 2018 - 21:32:43 EST


This patch adds to do sanity check with below fields of inode to
avoid reported panic.
- node footer
- iblocks

https://bugzilla.kernel.org/show_bug.cgi?id=200223

- Overview
BUG() triggered in f2fs_truncate_inode_blocks() when un-mounting a mounted f2fs image after writing to it

- Reproduce

- POC (poc.c)

static void activity(char *mpoint) {

char *foo_bar_baz;
int err;

static int buf[8192];
memset(buf, 0, sizeof(buf));

err = asprintf(&foo_bar_baz, "%s/foo/bar/baz", mpoint);

// open / write / read
int fd = open(foo_bar_baz, O_RDWR | O_TRUNC, 0777);
if (fd >= 0) {
write(fd, (char *)buf, 517);
write(fd, (char *)buf, sizeof(buf));
close(fd);
}

}

int main(int argc, char *argv[]) {
activity(argv[1]);
return 0;
}

- Kernel meesage
[ 552.479723] F2FS-fs (loop0): Mounted with checkpoint version = 2
[ 556.451891] ------------[ cut here ]------------
[ 556.451899] kernel BUG at fs/f2fs/node.c:987!
[ 556.452920] invalid opcode: 0000 [#1] SMP KASAN PTI
[ 556.453936] CPU: 1 PID: 1310 Comm: umount Not tainted 4.18.0-rc1+ #4
[ 556.455213] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[ 556.457140] RIP: 0010:f2fs_truncate_inode_blocks+0x4a7/0x6f0
[ 556.458280] Code: e8 ae ea ff ff 41 89 c7 c1 e8 1f 84 c0 74 0a 41 83 ff fe 0f 85 35 ff ff ff 81 85 b0 fe ff ff fb 03 00 00 e9 f7 fd ff ff 0f 0b <0f> 0b e8 62 b7 9a 00 48 8b bd a0 fe ff ff e8 56 54 ae ff 48 8b b5
[ 556.462015] RSP: 0018:ffff8801f292f808 EFLAGS: 00010286
[ 556.463068] RAX: ffffed003e73242d RBX: ffff8801f292f958 RCX: ffffffffb88b81bc
[ 556.464479] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8801f3992164
[ 556.465901] RBP: ffff8801f292f980 R08: ffffed003e73242d R09: ffffed003e73242d
[ 556.467311] R10: 0000000000000001 R11: ffffed003e73242c R12: 00000000fffffc64
[ 556.468706] R13: ffff8801f3992000 R14: 0000000000000058 R15: 00000000ffff8801
[ 556.470117] FS: 00007f8029297840(0000) GS:ffff8801f6f00000(0000) knlGS:0000000000000000
[ 556.471702] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 556.472838] CR2: 000055f5f57305d8 CR3: 00000001f18b0000 CR4: 00000000000006e0
[ 556.474265] Call Trace:
[ 556.474782] ? f2fs_alloc_nid_failed+0xf0/0xf0
[ 556.475686] ? truncate_nodes+0x980/0x980
[ 556.476516] ? pagecache_get_page+0x21f/0x2f0
[ 556.477412] ? __asan_loadN+0xf/0x20
[ 556.478153] ? __get_node_page+0x331/0x5b0
[ 556.478992] ? reweight_entity+0x1e6/0x3b0
[ 556.479826] f2fs_truncate_blocks+0x55e/0x740
[ 556.480709] ? f2fs_truncate_data_blocks+0x20/0x20
[ 556.481689] ? __radix_tree_lookup+0x34/0x160
[ 556.482630] ? radix_tree_lookup+0xd/0x10
[ 556.483445] f2fs_truncate+0xd4/0x1a0
[ 556.484206] f2fs_evict_inode+0x5ce/0x630
[ 556.485032] evict+0x16f/0x290
[ 556.485664] iput+0x280/0x300
[ 556.486300] dentry_unlink_inode+0x165/0x1e0
[ 556.487169] __dentry_kill+0x16a/0x260
[ 556.487936] dentry_kill+0x70/0x250
[ 556.488651] shrink_dentry_list+0x125/0x260
[ 556.489504] shrink_dcache_parent+0xc1/0x110
[ 556.490379] ? shrink_dcache_sb+0x200/0x200
[ 556.491231] ? bit_wait_timeout+0xc0/0xc0
[ 556.492047] do_one_tree+0x12/0x40
[ 556.492743] shrink_dcache_for_umount+0x3f/0xa0
[ 556.493656] generic_shutdown_super+0x43/0x1c0
[ 556.494561] kill_block_super+0x52/0x80
[ 556.495341] kill_f2fs_super+0x62/0x70
[ 556.496105] deactivate_locked_super+0x6f/0xa0
[ 556.497004] deactivate_super+0x5e/0x80
[ 556.497785] cleanup_mnt+0x61/0xa0
[ 556.498492] __cleanup_mnt+0x12/0x20
[ 556.499218] task_work_run+0xc8/0xf0
[ 556.499949] exit_to_usermode_loop+0x125/0x130
[ 556.500846] do_syscall_64+0x138/0x170
[ 556.501609] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 556.502659] RIP: 0033:0x7f8028b77487
[ 556.503384] Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 c9 2b 00 f7 d8 64 89 01 48
[ 556.507137] RSP: 002b:00007fff9f2e3598 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 556.508637] RAX: 0000000000000000 RBX: 0000000000ebd030 RCX: 00007f8028b77487
[ 556.510069] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000ec41e0
[ 556.511481] RBP: 0000000000ec41e0 R08: 0000000000000000 R09: 0000000000000014
[ 556.512892] R10: 00000000000006b2 R11: 0000000000000246 R12: 00007f802908083c
[ 556.514320] R13: 0000000000000000 R14: 0000000000ebd210 R15: 00007fff9f2e3820
[ 556.515745] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy
[ 556.529276] ---[ end trace 4ce02f25ff7d3df5 ]---
[ 556.530340] RIP: 0010:f2fs_truncate_inode_blocks+0x4a7/0x6f0
[ 556.531513] Code: e8 ae ea ff ff 41 89 c7 c1 e8 1f 84 c0 74 0a 41 83 ff fe 0f 85 35 ff ff ff 81 85 b0 fe ff ff fb 03 00 00 e9 f7 fd ff ff 0f 0b <0f> 0b e8 62 b7 9a 00 48 8b bd a0 fe ff ff e8 56 54 ae ff 48 8b b5
[ 556.535330] RSP: 0018:ffff8801f292f808 EFLAGS: 00010286
[ 556.536395] RAX: ffffed003e73242d RBX: ffff8801f292f958 RCX: ffffffffb88b81bc
[ 556.537824] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8801f3992164
[ 556.539290] RBP: ffff8801f292f980 R08: ffffed003e73242d R09: ffffed003e73242d
[ 556.540709] R10: 0000000000000001 R11: ffffed003e73242c R12: 00000000fffffc64
[ 556.542131] R13: ffff8801f3992000 R14: 0000000000000058 R15: 00000000ffff8801
[ 556.543579] FS: 00007f8029297840(0000) GS:ffff8801f6f00000(0000) knlGS:0000000000000000
[ 556.545180] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 556.546338] CR2: 000055f5f57305d8 CR3: 00000001f18b0000 CR4: 00000000000006e0
[ 556.547809] ==================================================================
[ 556.549248] BUG: KASAN: stack-out-of-bounds in arch_tlb_gather_mmu+0x52/0x170
[ 556.550672] Write of size 8 at addr ffff8801f292fd10 by task umount/1310

[ 556.552338] CPU: 1 PID: 1310 Comm: umount Tainted: G D 4.18.0-rc1+ #4
[ 556.553886] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[ 556.555756] Call Trace:
[ 556.556264] dump_stack+0x7b/0xb5
[ 556.556944] print_address_description+0x70/0x290
[ 556.557903] kasan_report+0x291/0x390
[ 556.558649] ? arch_tlb_gather_mmu+0x52/0x170
[ 556.559537] __asan_store8+0x57/0x90
[ 556.560268] arch_tlb_gather_mmu+0x52/0x170
[ 556.561110] tlb_gather_mmu+0x12/0x40
[ 556.561862] exit_mmap+0x123/0x2a0
[ 556.562555] ? __ia32_sys_munmap+0x50/0x50
[ 556.563384] ? exit_aio+0x98/0x230
[ 556.564079] ? __x32_compat_sys_io_submit+0x260/0x260
[ 556.565099] ? taskstats_exit+0x1f4/0x640
[ 556.565925] ? kasan_check_read+0x11/0x20
[ 556.566739] ? mm_update_next_owner+0x322/0x380
[ 556.567652] mmput+0x8b/0x1d0
[ 556.568260] do_exit+0x43a/0x1390
[ 556.568937] ? mm_update_next_owner+0x380/0x380
[ 556.569855] ? deactivate_super+0x5e/0x80
[ 556.570668] ? cleanup_mnt+0x61/0xa0
[ 556.571395] ? __cleanup_mnt+0x12/0x20
[ 556.572156] ? task_work_run+0xc8/0xf0
[ 556.572917] ? exit_to_usermode_loop+0x125/0x130
[ 556.573861] rewind_stack_do_exit+0x17/0x20
[ 556.574707] RIP: 0033:0x7f8028b77487
[ 556.575428] Code: Bad RIP value.
[ 556.576106] RSP: 002b:00007fff9f2e3598 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 556.577599] RAX: 0000000000000000 RBX: 0000000000ebd030 RCX: 00007f8028b77487
[ 556.579020] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000ec41e0
[ 556.580422] RBP: 0000000000ec41e0 R08: 0000000000000000 R09: 0000000000000014
[ 556.581833] R10: 00000000000006b2 R11: 0000000000000246 R12: 00007f802908083c
[ 556.583252] R13: 0000000000000000 R14: 0000000000ebd210 R15: 00007fff9f2e3820

[ 556.584983] The buggy address belongs to the page:
[ 556.585961] page:ffffea0007ca4bc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[ 556.587540] flags: 0x2ffff0000000000()
[ 556.588296] raw: 02ffff0000000000 0000000000000000 dead000000000200 0000000000000000
[ 556.589822] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[ 556.591359] page dumped because: kasan: bad access detected

[ 556.592786] Memory state around the buggy address:
[ 556.593753] ffff8801f292fc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 556.595191] ffff8801f292fc80: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00
[ 556.596613] >ffff8801f292fd00: 00 00 f3 00 00 00 00 f3 f3 00 00 00 00 f4 f4 f4
[ 556.598044] ^
[ 556.598797] ffff8801f292fd80: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
[ 556.600225] ffff8801f292fe00: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f4 f4 f4
[ 556.601647] ==================================================================

- Location
https://elixir.bootlin.com/linux/v4.18-rc1/source/fs/f2fs/node.c#L987
case NODE_DIND_BLOCK:
err = truncate_nodes(&dn, nofs, offset[1], 3);
cont = 0;
break;

default:
BUG(); <---
}

Reported-by Wen Xu <wen.xu@xxxxxxxxxx>
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
v2:
- remove incorrect upper boundary check for iblock.
fs/f2fs/inode.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 22810d30c054..f490393397d4 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -193,9 +193,30 @@ void f2fs_inode_chksum_set(struct f2fs_sb_info *sbi, struct page *page)
ri->i_inode_checksum = cpu_to_le32(f2fs_inode_chksum(sbi, page));
}

-static bool sanity_check_inode(struct inode *inode)
+static bool sanity_check_inode(struct inode *inode, struct page *node_page)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ unsigned long long iblocks;
+
+ iblocks = le64_to_cpu(F2FS_INODE(node_page)->i_blocks);
+ if (!iblocks) {
+ set_sbi_flag(sbi, SBI_NEED_FSCK);
+ f2fs_msg(sbi->sb, KERN_WARNING,
+ "%s: corrupted inode i_blocks i_ino=%lx iblocks=%llu, "
+ "run fsck to fix.",
+ __func__, inode->i_ino, iblocks);
+ return false;
+ }
+
+ if (ino_of_node(node_page) != nid_of_node(node_page)) {
+ set_sbi_flag(sbi, SBI_NEED_FSCK);
+ f2fs_msg(sbi->sb, KERN_WARNING,
+ "%s: corrupted inode footer i_ino=%lx, ino,nid: "
+ "[%u, %u] run fsck to fix.",
+ __func__, inode->i_ino,
+ ino_of_node(node_page), nid_of_node(node_page));
+ return false;
+ }

if (f2fs_sb_has_flexible_inline_xattr(sbi->sb)
&& !f2fs_has_extra_attr(inode)) {
@@ -267,7 +288,7 @@ static int do_read_inode(struct inode *inode)

get_inline_info(inode, ri);

- if (!sanity_check_inode(inode)) {
+ if (!sanity_check_inode(inode, node_page)) {
f2fs_put_page(node_page, 1);
return -EINVAL;
}
--
2.18.0.rc1