diff mbox series

[5.10,052/390] f2fs: fix to do sanity check on summary info

Message ID 20221024113024.853480982@linuxfoundation.org
State New
Headers
Series None |

Commit Message

Greg KH Oct. 24, 2022, 11:27 a.m. UTC 
  From: Chao Yu <chao@kernel.org>

commit c6ad7fd16657ebd34a87a97d9588195aae87597d upstream.

As Wenqing Liu reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=216456

BUG: KASAN: use-after-free in recover_data+0x63ae/0x6ae0 [f2fs]
Read of size 4 at addr ffff8881464dcd80 by task mount/1013

CPU: 3 PID: 1013 Comm: mount Tainted: G        W          6.0.0-rc4 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
Call Trace:
 dump_stack_lvl+0x45/0x5e
 print_report.cold+0xf3/0x68d
 kasan_report+0xa8/0x130
 recover_data+0x63ae/0x6ae0 [f2fs]
 f2fs_recover_fsync_data+0x120d/0x1fc0 [f2fs]
 f2fs_fill_super+0x4665/0x61e0 [f2fs]
 mount_bdev+0x2cf/0x3b0
 legacy_get_tree+0xed/0x1d0
 vfs_get_tree+0x81/0x2b0
 path_mount+0x47e/0x19d0
 do_mount+0xce/0xf0
 __x64_sys_mount+0x12c/0x1a0
 do_syscall_64+0x38/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The root cause is: in fuzzed image, SSA table is corrupted: ofs_in_node
is larger than ADDRS_PER_PAGE(), result in out-of-range access on 4k-size
page.

- recover_data
 - do_recover_data
  - check_index_in_prev_nodes
   - f2fs_data_blkaddr

This patch adds sanity check on summary info in recovery and GC flow
in where the flows rely on them.

After patch:
[   29.310883] F2FS-fs (loop0): Inconsistent ofs_in_node:65286 in summary, ino:0, nid:6, max:1018

Cc: stable@vger.kernel.org
Reported-by: Wenqing Liu <wenqingliu0120@gmail.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>
---
 fs/f2fs/gc.c       |   10 +++++++++-
 fs/f2fs/recovery.c |   15 ++++++++++++---
 2 files changed, 21 insertions(+), 4 deletions(-)

Comments

Pavel Machek Oct. 24, 2022, 5:30 p.m. UTC | #1 
Hi!

> From: Chao Yu <chao@kernel.org>
> 
> commit c6ad7fd16657ebd34a87a97d9588195aae87597d upstream.
> 
> As Wenqing Liu reported in bugzilla:
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=216456
> 
> BUG: KASAN: use-after-free in recover_data+0x63ae/0x6ae0 [f2fs]
> Read of size 4 at addr ffff8881464dcd80 by task mount/1013

I believe this is missing put_page on the error path:

> +++ b/fs/f2fs/gc.c
> @@ -1003,6 +1003,14 @@ static bool is_alive(struct f2fs_sb_info
>  		return false;
>  	}
>  
> +	max_addrs = IS_INODE(node_page) ? DEF_ADDRS_PER_INODE :
> +						DEF_ADDRS_PER_BLOCK;
> +	if (ofs_in_node >= max_addrs) {
> +		f2fs_err(sbi, "Inconsistent ofs_in_node:%u in summary, ino:%u, nid:%u, max:%u",
> +			ofs_in_node, dni->ino, dni->nid, max_addrs);
> +		return false;
> +	}
> +
>  	*nofs = ofs_of_node(node_page);
>  	source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
>  	f2fs_put_page(node_page, 1);

So something like this is needed. (Feel free to test/adapt/apply).

Signed-off-by: Pavel Machek <pavel@denx.de>

Best regards,
								Pavel

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 4546e01b2ee0..dab794225cce 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -1110,6 +1110,7 @@ static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 	if (ofs_in_node >= max_addrs) {
 		f2fs_err(sbi, "Inconsistent ofs_in_node:%u in summary, ino:%u, nid:%u, max:%u",
 			ofs_in_node, dni->ino, dni->nid, max_addrs);
+		f2fs_put_page(node_page, 1);
 		return false;
 	}
Jaegeuk Kim Oct. 24, 2022, 6:08 p.m. UTC | #2 
On 10/24, Pavel Machek wrote:
> Hi!
> 
> > From: Chao Yu <chao@kernel.org>
> > 
> > commit c6ad7fd16657ebd34a87a97d9588195aae87597d upstream.
> > 
> > As Wenqing Liu reported in bugzilla:
> > 
> > https://bugzilla.kernel.org/show_bug.cgi?id=216456
> > 
> > BUG: KASAN: use-after-free in recover_data+0x63ae/0x6ae0 [f2fs]
> > Read of size 4 at addr ffff8881464dcd80 by task mount/1013
> 
> I believe this is missing put_page on the error path:
> 
> > +++ b/fs/f2fs/gc.c
> > @@ -1003,6 +1003,14 @@ static bool is_alive(struct f2fs_sb_info
> >  		return false;
> >  	}
> >  
> > +	max_addrs = IS_INODE(node_page) ? DEF_ADDRS_PER_INODE :
> > +						DEF_ADDRS_PER_BLOCK;
> > +	if (ofs_in_node >= max_addrs) {
> > +		f2fs_err(sbi, "Inconsistent ofs_in_node:%u in summary, ino:%u, nid:%u, max:%u",
> > +			ofs_in_node, dni->ino, dni->nid, max_addrs);
> > +		return false;
> > +	}
> > +
> >  	*nofs = ofs_of_node(node_page);
> >  	source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
> >  	f2fs_put_page(node_page, 1);
> 
> So something like this is needed. (Feel free to test/adapt/apply).

Urg.. thank you so much for pointing this out. Applied the change to the tree.

https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/commit/?h=dev&id=a22aeafb3d3569aecf811dca1aceff656695cdb4

> 
> Signed-off-by: Pavel Machek <pavel@denx.de>
> 
> Best regards,
> 								Pavel
> 
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 4546e01b2ee0..dab794225cce 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -1110,6 +1110,7 @@ static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
>  	if (ofs_in_node >= max_addrs) {
>  		f2fs_err(sbi, "Inconsistent ofs_in_node:%u in summary, ino:%u, nid:%u, max:%u",
>  			ofs_in_node, dni->ino, dni->nid, max_addrs);
> +		f2fs_put_page(node_page, 1);
>  		return false;
>  	}
>  
> 
> -- 
> DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Chao Yu Oct. 25, 2022, 2:53 a.m. UTC | #3 
On 2022/10/25 1:30, Pavel Machek wrote:
> Hi!
> 
>> From: Chao Yu <chao@kernel.org>
>>
>> commit c6ad7fd16657ebd34a87a97d9588195aae87597d upstream.
>>
>> As Wenqing Liu reported in bugzilla:
>>
>> https://bugzilla.kernel.org/show_bug.cgi?id=216456
>>
>> BUG: KASAN: use-after-free in recover_data+0x63ae/0x6ae0 [f2fs]
>> Read of size 4 at addr ffff8881464dcd80 by task mount/1013
> 
> I believe this is missing put_page on the error path:
> 
>> +++ b/fs/f2fs/gc.c
>> @@ -1003,6 +1003,14 @@ static bool is_alive(struct f2fs_sb_info
>>   		return false;
>>   	}
>>   
>> +	max_addrs = IS_INODE(node_page) ? DEF_ADDRS_PER_INODE :
>> +						DEF_ADDRS_PER_BLOCK;
>> +	if (ofs_in_node >= max_addrs) {
>> +		f2fs_err(sbi, "Inconsistent ofs_in_node:%u in summary, ino:%u, nid:%u, max:%u",
>> +			ofs_in_node, dni->ino, dni->nid, max_addrs);
>> +		return false;
>> +	}
>> +
>>   	*nofs = ofs_of_node(node_page);
>>   	source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
>>   	f2fs_put_page(node_page, 1);
> 
> So something like this is needed. (Feel free to test/adapt/apply).
> 
> Signed-off-by: Pavel Machek <pavel@denx.de>
> 
> Best regards,
> 								Pavel
> 
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 4546e01b2ee0..dab794225cce 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -1110,6 +1110,7 @@ static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
>   	if (ofs_in_node >= max_addrs) {
>   		f2fs_err(sbi, "Inconsistent ofs_in_node:%u in summary, ino:%u, nid:%u, max:%u",
>   			ofs_in_node, dni->ino, dni->nid, max_addrs);
> +		f2fs_put_page(node_page, 1);
>   		return false;
>   	}

My bad, thanks for fixing this.

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,

>   
>
diff mbox series

Patch

--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -977,7 +977,7 @@  static bool is_alive(struct f2fs_sb_info
 {
 	struct page *node_page;
 	nid_t nid;
-	unsigned int ofs_in_node;
+	unsigned int ofs_in_node, max_addrs;
 	block_t source_blkaddr;
 
 	nid = le32_to_cpu(sum->nid);
@@ -1003,6 +1003,14 @@  static bool is_alive(struct f2fs_sb_info
 		return false;
 	}
 
+	max_addrs = IS_INODE(node_page) ? DEF_ADDRS_PER_INODE :
+						DEF_ADDRS_PER_BLOCK;
+	if (ofs_in_node >= max_addrs) {
+		f2fs_err(sbi, "Inconsistent ofs_in_node:%u in summary, ino:%u, nid:%u, max:%u",
+			ofs_in_node, dni->ino, dni->nid, max_addrs);
+		return false;
+	}
+
 	*nofs = ofs_of_node(node_page);
 	source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
 	f2fs_put_page(node_page, 1);
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -437,7 +437,7 @@  static int check_index_in_prev_nodes(str
 	struct dnode_of_data tdn = *dn;
 	nid_t ino, nid;
 	struct inode *inode;
-	unsigned int offset;
+	unsigned int offset, ofs_in_node, max_addrs;
 	block_t bidx;
 	int i;
 
@@ -463,15 +463,24 @@  static int check_index_in_prev_nodes(str
 got_it:
 	/* Use the locked dnode page and inode */
 	nid = le32_to_cpu(sum.nid);
+	ofs_in_node = le16_to_cpu(sum.ofs_in_node);
+
+	max_addrs = ADDRS_PER_PAGE(dn->node_page, dn->inode);
+	if (ofs_in_node >= max_addrs) {
+		f2fs_err(sbi, "Inconsistent ofs_in_node:%u in summary, ino:%lu, nid:%u, max:%u",
+			ofs_in_node, dn->inode->i_ino, nid, max_addrs);
+		return -EFSCORRUPTED;
+	}
+
 	if (dn->inode->i_ino == nid) {
 		tdn.nid = nid;
 		if (!dn->inode_page_locked)
 			lock_page(dn->inode_page);
 		tdn.node_page = dn->inode_page;
-		tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
+		tdn.ofs_in_node = ofs_in_node;
 		goto truncate_out;
 	} else if (dn->nid == nid) {
-		tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
+		tdn.ofs_in_node = ofs_in_node;
 		goto truncate_out;
 	}