diff options
author | Qu Wenruo <wqu@suse.com> | 2024-06-24 08:40:53 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-07-11 13:51:11 +0300 |
commit | ebe5ea02577b2c527958af1b76ac472c7ab53a56 (patch) | |
tree | 480d652ac518ca944e143d270760293017027a4d | |
parent | efdc3f54299835ddef23bea651c753c4d467010b (diff) | |
download | linux-ebe5ea02577b2c527958af1b76ac472c7ab53a56.tar.xz |
btrfs: always do the basic checks for btrfs_qgroup_inherit structure
[ Upstream commit 724d8042cef84496ddb4492dc120291f997ae26b ]
[BUG]
Syzbot reports the following regression detected by KASAN:
BUG: KASAN: slab-out-of-bounds in btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup.c:3277
Read of size 8 at addr ffff88814628ca50 by task syz-executor318/5171
CPU: 0 PID: 5171 Comm: syz-executor318 Not tainted 6.10.0-rc2-syzkaller-00010-g2ab795141095 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup.c:3277
create_pending_snapshot+0x1359/0x29b0 fs/btrfs/transaction.c:1854
create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1922
btrfs_commit_transaction+0xf20/0x3740 fs/btrfs/transaction.c:2382
create_snapshot+0x6a1/0x9e0 fs/btrfs/ioctl.c:875
btrfs_mksubvol+0x58f/0x710 fs/btrfs/ioctl.c:1029
btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1075
__btrfs_ioctl_snap_create+0x387/0x4b0 fs/btrfs/ioctl.c:1340
btrfs_ioctl_snap_create_v2+0x1f2/0x3a0 fs/btrfs/ioctl.c:1422
btrfs_ioctl+0x99e/0xc60
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcbf1992509
RSP: 002b:00007fcbf1928218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcbf1a1f618 RCX: 00007fcbf1992509
RDX: 0000000020000280 RSI: 0000000050009417 RDI: 0000000000000003
RBP: 00007fcbf1a1f610 R08: 00007ffea1298e97 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcbf19eb660
R13: 00000000200002b8 R14: 00007fcbf19e60c0 R15: 0030656c69662f2e
</TASK>
And it also pinned it down to commit b5357cb268c4 ("btrfs: qgroup: do not
check qgroup inherit if qgroup is disabled").
[CAUSE]
That offending commit skips the whole qgroup inherit check if qgroup is
not enabled.
But that also skips the very basic checks like
num_ref_copies/num_excl_copies and the structure size checks.
Meaning if a qgroup enable/disable race is happening at the background,
and we pass a btrfs_qgroup_inherit structure when the qgroup is
disabled, the check would be completely skipped.
Then at the time of transaction commitment, qgroup is re-enabled and
btrfs_qgroup_inherit() is going to use the incorrect structure and
causing the above KASAN error.
[FIX]
Make btrfs_qgroup_check_inherit() only skip the source qgroup checks.
So that even if invalid btrfs_qgroup_inherit structure is passed in, we
can still reject invalid ones no matter if qgroup is enabled or not.
Furthermore we do already have an extra safety inside
btrfs_qgroup_inherit(), which would just ignore invalid qgroup sources,
so even if we only skip the qgroup source check we're still safe.
Reported-by: syzbot+a0d1f7e26910be4dc171@syzkaller.appspotmail.com
Fixes: b5357cb268c4 ("btrfs: qgroup: do not check qgroup inherit if qgroup is disabled")
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Jeongjun Park <aha310510@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r-- | fs/btrfs/qgroup.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 1167899a16d0..4caa078d972a 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -3065,8 +3065,6 @@ int btrfs_qgroup_check_inherit(struct btrfs_fs_info *fs_info, struct btrfs_qgroup_inherit *inherit, size_t size) { - if (!btrfs_qgroup_enabled(fs_info)) - return 0; if (inherit->flags & ~BTRFS_QGROUP_INHERIT_FLAGS_SUPP) return -EOPNOTSUPP; if (size < sizeof(*inherit) || size > PAGE_SIZE) @@ -3091,6 +3089,14 @@ int btrfs_qgroup_check_inherit(struct btrfs_fs_info *fs_info, return -EINVAL; /* + * Skip the inherit source qgroups check if qgroup is not enabled. + * Qgroup can still be later enabled causing problems, but in that case + * btrfs_qgroup_inherit() would just ignore those invalid ones. + */ + if (!btrfs_qgroup_enabled(fs_info)) + return 0; + + /* * Now check all the remaining qgroups, they should all: * * - Exist |