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authorChao Yu <chao@kernel.org>2023-06-29 19:11:44 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-08-11 12:08:24 +0200
commita78a8bcdc26de5ef3a0ee27c9c6c512e54a6051c (patch)
treee1464e9ee737e06cb1ff72d22f0e097f966be5d8 /include
parent23e72231f8281505883514b23709076e234d4f27 (diff)
downloadlinux-a78a8bcdc26de5ef3a0ee27c9c6c512e54a6051c.tar.gz
f2fs: fix to do sanity check on direct node in truncate_dnode()
commit a6ec83786ab9f13f25fb18166dee908845713a95 upstream.

syzbot reports below bug:

BUG: KASAN: slab-use-after-free in f2fs_truncate_data_blocks_range+0x122a/0x14c0 fs/f2fs/file.c:574
Read of size 4 at addr ffff88802a25c000 by task syz-executor148/5000

CPU: 1 PID: 5000 Comm: syz-executor148 Not tainted 6.4.0-rc7-syzkaller-00041-ge660abd551f1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351
 print_report mm/kasan/report.c:462 [inline]
 kasan_report+0x11c/0x130 mm/kasan/report.c:572
 f2fs_truncate_data_blocks_range+0x122a/0x14c0 fs/f2fs/file.c:574
 truncate_dnode+0x229/0x2e0 fs/f2fs/node.c:944
 f2fs_truncate_inode_blocks+0x64b/0xde0 fs/f2fs/node.c:1154
 f2fs_do_truncate_blocks+0x4ac/0xf30 fs/f2fs/file.c:721
 f2fs_truncate_blocks+0x7b/0x300 fs/f2fs/file.c:749
 f2fs_truncate.part.0+0x4a5/0x630 fs/f2fs/file.c:799
 f2fs_truncate include/linux/fs.h:825 [inline]
 f2fs_setattr+0x1738/0x2090 fs/f2fs/file.c:1006
 notify_change+0xb2c/0x1180 fs/attr.c:483
 do_truncate+0x143/0x200 fs/open.c:66
 handle_truncate fs/namei.c:3295 [inline]
 do_open fs/namei.c:3640 [inline]
 path_openat+0x2083/0x2750 fs/namei.c:3791
 do_filp_open+0x1ba/0x410 fs/namei.c:3818
 do_sys_openat2+0x16d/0x4c0 fs/open.c:1356
 do_sys_open fs/open.c:1372 [inline]
 __do_sys_creat fs/open.c:1448 [inline]
 __se_sys_creat fs/open.c:1442 [inline]
 __x64_sys_creat+0xcd/0x120 fs/open.c:1442
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The root cause is, inodeA references inodeB via inodeB's ino, once inodeA
is truncated, it calls truncate_dnode() to truncate data blocks in inodeB's
node page, it traverse mapping data from node->i.i_addr[0] to
node->i.i_addr[ADDRS_PER_BLOCK() - 1], result in out-of-boundary access.

This patch fixes to add sanity check on dnode page in truncate_dnode(),
so that, it can help to avoid triggering such issue, and once it encounters
such issue, it will record newly introduced ERROR_INVALID_NODE_REFERENCE
error into superblock, later fsck can detect such issue and try repairing.

Also, it removes f2fs_truncate_data_blocks() for cleanup due to the
function has only one caller, and uses f2fs_truncate_data_blocks_range()
instead.

Reported-and-tested-by: syzbot+12cb4425b22169b52036@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-f2fs-devel/000000000000f3038a05fef867f8@google.com
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/f2fs_fs.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index ee0d75d9a302..77055b239165 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -104,6 +104,7 @@ enum f2fs_error {
 	ERROR_INCONSISTENT_SIT,
 	ERROR_CORRUPTED_VERITY_XATTR,
 	ERROR_CORRUPTED_XATTR,
+	ERROR_INVALID_NODE_REFERENCE,
 	ERROR_MAX,
 };