* [PATCH 1/2] quota: check block number when reading the block in quota file
2021-10-08 9:38 [PATCH 0/2] quota: fix oops when loading corrupted quota file Zhang Yi
@ 2021-10-08 9:38 ` Zhang Yi
2021-10-08 9:38 ` [PATCH 2/2] qupta: correct error number in free_dqentry() Zhang Yi
2021-10-11 8:58 ` [PATCH 0/2] quota: fix oops when loading corrupted quota file Jan Kara
2 siblings, 0 replies; 4+ messages in thread
From: Zhang Yi @ 2021-10-08 9:38 UTC (permalink / raw)
To: linux-fsdevel; +Cc: jack, yi.zhang, yukuai3
The block number in the quota tree on disk should smaller than the
v2_disk_dqinfo.dqi_blocks. If the quota file was corrupted, we may
allocating an 'allocated' block and lead to the tree infinite loop,
which may probably trigger oops later. This patch add a check for
getting block number in the quota tree to prevent such potential issue.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Cc: stable@kernel.org
---
fs/quota/quota_tree.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c
index d3e995e1046f..583b7f7715f9 100644
--- a/fs/quota/quota_tree.c
+++ b/fs/quota/quota_tree.c
@@ -479,6 +479,13 @@ static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
goto out_buf;
}
newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
+ if (newblk < QT_TREEOFF || newblk >= info->dqi_blocks) {
+ quota_error(dquot->dq_sb, "Getting block too big (%u >= %u)",
+ newblk, info->dqi_blocks);
+ ret = -EUCLEAN;
+ goto out_buf;
+ }
+
if (depth == info->dqi_qtree_depth - 1) {
ret = free_dqentry(info, dquot, newblk);
newblk = 0;
@@ -578,6 +585,13 @@ static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info,
blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
if (!blk) /* No reference? */
goto out_buf;
+ if (blk < QT_TREEOFF || blk >= info->dqi_blocks) {
+ quota_error(dquot->dq_sb, "Getting block too big (%u >= %u)",
+ blk, info->dqi_blocks);
+ ret = -EUCLEAN;
+ goto out_buf;
+ }
+
if (depth < info->dqi_qtree_depth - 1)
ret = find_tree_dqentry(info, dquot, blk, depth+1);
else
--
2.31.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 2/2] qupta: correct error number in free_dqentry()
2021-10-08 9:38 [PATCH 0/2] quota: fix oops when loading corrupted quota file Zhang Yi
2021-10-08 9:38 ` [PATCH 1/2] quota: check block number when reading the block in " Zhang Yi
@ 2021-10-08 9:38 ` Zhang Yi
2021-10-11 8:58 ` [PATCH 0/2] quota: fix oops when loading corrupted quota file Jan Kara
2 siblings, 0 replies; 4+ messages in thread
From: Zhang Yi @ 2021-10-08 9:38 UTC (permalink / raw)
To: linux-fsdevel; +Cc: jack, yi.zhang, yukuai3
Fix the error path in free_dqentry(), pass out the error number if the
freeing block is not correct.
Fixes: 1ccd14b9c271c ("quota: Split off quota tree handling into a separate file")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Cc: stable@kernel.org
---
fs/quota/quota_tree.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c
index 583b7f7715f9..5f2405994280 100644
--- a/fs/quota/quota_tree.c
+++ b/fs/quota/quota_tree.c
@@ -414,6 +414,7 @@ static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
quota_error(dquot->dq_sb, "Quota structure has offset to "
"other block (%u) than it should (%u)", blk,
(uint)(dquot->dq_off >> info->dqi_blocksize_bits));
+ ret = -EIO;
goto out_buf;
}
ret = read_blk(info, blk, buf);
--
2.31.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH 0/2] quota: fix oops when loading corrupted quota file
2021-10-08 9:38 [PATCH 0/2] quota: fix oops when loading corrupted quota file Zhang Yi
2021-10-08 9:38 ` [PATCH 1/2] quota: check block number when reading the block in " Zhang Yi
2021-10-08 9:38 ` [PATCH 2/2] qupta: correct error number in free_dqentry() Zhang Yi
@ 2021-10-11 8:58 ` Jan Kara
2 siblings, 0 replies; 4+ messages in thread
From: Jan Kara @ 2021-10-11 8:58 UTC (permalink / raw)
To: Zhang Yi; +Cc: linux-fsdevel, jack, yukuai3
On Fri 08-10-21 17:38:19, Zhang Yi wrote:
> We hit an oops issue on our Syzkaller machine, it test on an corrupted
> ext4 filesystem image with quota feature.
>
> BUG: unable to handle page fault for address: ffffffffd9c01f8d
> PGD 732e0f067 P4D 732e0f067 PUD 732e11067 PMD 0
> Oops: 0000 [#1] SMP PTI
> CPU: 5 PID: 1282 Comm: chown Not tainted 5.15.0-rc4-00019-g5af4055fa813 #572
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31
> 04/01/2014
> RIP: 0010:do_raw_spin_lock+0x6/0x190
> Code: e8 00 44 8b 4d 08 48 85 db 0f 84 c5 b9 e8 00 e9 fd b9 e8 00 48 83
> 05 d0 ec cc 02 01 31 db eb b0 0f 1f 40 00 0f 1f 44 00 00 53 <8b> 47 04
> 48 89 fb 48 83 05 0c ee cc 02 01 48 83 05 e4 ec cc 02 01
> RSP: 0018:ffffac4140be7b78 EFLAGS: 00010202
> RAX: 0000000000000000 RBX: ffffffffd9c01f11 RCX: 0000000000000000
> RDX: ffffac4140be7c00 RSI: 0000000000000001 RDI: ffffffffd9c01f89
> RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000002
> R10: 0000000000000001 R11: 0000000000000005 R12: ffffac4140be7c00
> R13: ffffffffd9c01f89 R14: ffffac4140be7d20 R15: 0000000000000000
> FS: 00007efd702dc580(0000) GS:ffff889ca5740000(0000)
> knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: ffffffffd9c01f8d CR3: 000000015dae8000 CR4: 00000000000006e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> _raw_spin_lock+0x1a/0x30
> dquot_add_inodes+0x28/0x2a0
> __dquot_transfer+0x3af/0x8e0
> ? jbd2_journal_stop+0x213/0x510
> ? __ext4_journal_stop+0x43/0x110
> ? ext4_acquire_dquot+0xb2/0x120
> ? dqget+0x317/0x710
> dquot_transfer+0xaa/0x1f0
> ext4_setattr+0x1b1/0xf20
> ? path_lookupat.isra.0+0xca/0x200
> notify_change+0x484/0x790
> ? chown_common+0x16e/0x2f0
> chown_common+0x16e/0x2f0
> do_fchownat+0x107/0x180
> __x64_sys_fchownat+0x29/0x40
> do_syscall_64+0x3b/0x90
>
> We could 100% reproduce it through the following simple test case. The
> first patche add some block validity check and the second patch fix an
> incorrect return value.
>
>
> TEST_DEV=/dev/pmem0
>
> useradd fsgqa
> useradd 123456-fsgqa
>
> mkfs.ext4 -F -O quota -b 1024 $TEST_DEV
> debugfs -w -R "zap_block -o 0 -l 1 -p 6 -f <3> 1" $TEST_DEV
> mount $TEST_DEV /mnt
> chown fsgqa:fsgqa /mnt
> touch /mnt/foo
> rm -f /mnt/foo
> chown 123456-fsgqa:123456-fsgqa /mnt
>
>
> Thanks,
> Yi.
>
> Zhang Yi (2):
> quota: check block number when reading the block in quota file
> qupta: correct error number in free_dqentry()
Thanks, I've merged both patches into my tree with some minor spelling
fixes.
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 4+ messages in thread