diff mbox series

[v2] ext4: fix WARNING in ext4_expand_extra_isize_ea

Message ID 20221201145923.73028-1-yebin@huaweicloud.com
State New
Headers
Series [v2] ext4: fix WARNING in ext4_expand_extra_isize_ea |

Commit Message

Ye Bin Dec. 1, 2022, 2:59 p.m. UTC 
  From: Ye Bin <yebin10@huawei.com>

Syzbot found the following issue:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 3631 at mm/page_alloc.c:5534 __alloc_pages+0x30a/0x560 mm/page_alloc.c:5534
Modules linked in:
CPU: 1 PID: 3631 Comm: syz-executor261 Not tainted 6.1.0-rc6-syzkaller-00308-g644e9524388a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:__alloc_pages+0x30a/0x560 mm/page_alloc.c:5534
RSP: 0018:ffffc90003ccf080 EFLAGS: 00010246
RAX: ffffc90003ccf0e0 RBX: 000000000000000c RCX: 0000000000000000
RDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc90003ccf108
RBP: ffffc90003ccf198 R08: dffffc0000000000 R09: ffffc90003ccf0e0
R10: fffff52000799e21 R11: 1ffff92000799e1c R12: 0000000000040c40
R13: 1ffff92000799e18 R14: dffffc0000000000 R15: 1ffff92000799e14
FS:  0000555555c10300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc36f70000 CR3: 00000000744ad000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __alloc_pages_node include/linux/gfp.h:223 [inline]
 alloc_pages_node include/linux/gfp.h:246 [inline]
 __kmalloc_large_node+0x8a/0x1a0 mm/slab_common.c:1096
 __do_kmalloc_node mm/slab_common.c:943 [inline]
 __kmalloc+0xfe/0x1a0 mm/slab_common.c:968
 kmalloc include/linux/slab.h:558 [inline]
 ext4_xattr_move_to_block fs/ext4/xattr.c:2558 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2673 [inline]
 ext4_expand_extra_isize_ea+0xe3f/0x1cd0 fs/ext4/xattr.c:2765
 __ext4_expand_extra_isize+0x2b8/0x3f0 fs/ext4/inode.c:5857
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5900 [inline]
 __ext4_mark_inode_dirty+0x51a/0x670 fs/ext4/inode.c:5978
 ext4_inline_data_truncate+0x548/0xd00 fs/ext4/inline.c:2021
 ext4_truncate+0x341/0xeb0 fs/ext4/inode.c:4221
 ext4_process_orphan+0x1aa/0x2d0 fs/ext4/orphan.c:339
 ext4_orphan_cleanup+0xb60/0x1340 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5515 [inline]
 ext4_fill_super+0x80ed/0x8610 fs/ext4/super.c:5643
 get_tree_bdev+0x400/0x620 fs/super.c:1324
 vfs_get_tree+0x88/0x270 fs/super.c:1531
 do_new_mount+0x289/0xad0 fs/namespace.c:3040
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3568
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
 </TASK>

Reason is allocate 16M memory by kmalloc, but MAX_ORDER is 11, kmalloc
can allocate maxium size memory is 4M.
XATTR_SIZE_MAX is currently 64k, but EXT4_XATTR_SIZE_MAX is '(1 << 24)',
so 'ext4_xattr_check_entries()' regards this length as legal. Then trigger
warning in 'ext4_xattr_move_to_block()'.
To solve above issue, according to Jan Kara's suggestion use kvmalloc()
to allocate memory in ext4_xattr_move_to_block().

Reported-by: syzbot+4d99a966fd74bdeeec36@syzkaller.appspotmail.com
Fixes: 54dd0e0a1b25 ("ext4: add extra checks to ext4_xattr_block_get()")
Signed-off-by: Ye Bin <yebin10@huawei.com>
---
 fs/ext4/xattr.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Jan Kara Dec. 1, 2022, 3:33 p.m. UTC | #1 
On Thu 01-12-22 22:59:23, Ye Bin wrote:
> From: Ye Bin <yebin10@huawei.com>
> 
> Syzbot found the following issue:
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 3631 at mm/page_alloc.c:5534 __alloc_pages+0x30a/0x560 mm/page_alloc.c:5534
> Modules linked in:
> CPU: 1 PID: 3631 Comm: syz-executor261 Not tainted 6.1.0-rc6-syzkaller-00308-g644e9524388a #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
> RIP: 0010:__alloc_pages+0x30a/0x560 mm/page_alloc.c:5534
> RSP: 0018:ffffc90003ccf080 EFLAGS: 00010246
> RAX: ffffc90003ccf0e0 RBX: 000000000000000c RCX: 0000000000000000
> RDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc90003ccf108
> RBP: ffffc90003ccf198 R08: dffffc0000000000 R09: ffffc90003ccf0e0
> R10: fffff52000799e21 R11: 1ffff92000799e1c R12: 0000000000040c40
> R13: 1ffff92000799e18 R14: dffffc0000000000 R15: 1ffff92000799e14
> FS:  0000555555c10300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007ffc36f70000 CR3: 00000000744ad000 CR4: 00000000003506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  __alloc_pages_node include/linux/gfp.h:223 [inline]
>  alloc_pages_node include/linux/gfp.h:246 [inline]
>  __kmalloc_large_node+0x8a/0x1a0 mm/slab_common.c:1096
>  __do_kmalloc_node mm/slab_common.c:943 [inline]
>  __kmalloc+0xfe/0x1a0 mm/slab_common.c:968
>  kmalloc include/linux/slab.h:558 [inline]
>  ext4_xattr_move_to_block fs/ext4/xattr.c:2558 [inline]
>  ext4_xattr_make_inode_space fs/ext4/xattr.c:2673 [inline]
>  ext4_expand_extra_isize_ea+0xe3f/0x1cd0 fs/ext4/xattr.c:2765
>  __ext4_expand_extra_isize+0x2b8/0x3f0 fs/ext4/inode.c:5857
>  ext4_try_to_expand_extra_isize fs/ext4/inode.c:5900 [inline]
>  __ext4_mark_inode_dirty+0x51a/0x670 fs/ext4/inode.c:5978
>  ext4_inline_data_truncate+0x548/0xd00 fs/ext4/inline.c:2021
>  ext4_truncate+0x341/0xeb0 fs/ext4/inode.c:4221
>  ext4_process_orphan+0x1aa/0x2d0 fs/ext4/orphan.c:339
>  ext4_orphan_cleanup+0xb60/0x1340 fs/ext4/orphan.c:474
>  __ext4_fill_super fs/ext4/super.c:5515 [inline]
>  ext4_fill_super+0x80ed/0x8610 fs/ext4/super.c:5643
>  get_tree_bdev+0x400/0x620 fs/super.c:1324
>  vfs_get_tree+0x88/0x270 fs/super.c:1531
>  do_new_mount+0x289/0xad0 fs/namespace.c:3040
>  do_mount fs/namespace.c:3383 [inline]
>  __do_sys_mount fs/namespace.c:3591 [inline]
>  __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3568
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
>  </TASK>
> 
> Reason is allocate 16M memory by kmalloc, but MAX_ORDER is 11, kmalloc
> can allocate maxium size memory is 4M.
> XATTR_SIZE_MAX is currently 64k, but EXT4_XATTR_SIZE_MAX is '(1 << 24)',
> so 'ext4_xattr_check_entries()' regards this length as legal. Then trigger
> warning in 'ext4_xattr_move_to_block()'.
> To solve above issue, according to Jan Kara's suggestion use kvmalloc()
> to allocate memory in ext4_xattr_move_to_block().
> 
> Reported-by: syzbot+4d99a966fd74bdeeec36@syzkaller.appspotmail.com
> Fixes: 54dd0e0a1b25 ("ext4: add extra checks to ext4_xattr_block_get()")
> Signed-off-by: Ye Bin <yebin10@huawei.com>

Thanks! The patch looks good to me. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/ext4/xattr.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
> index 718ef3987f94..23cfefc6d262 100644
> --- a/fs/ext4/xattr.c
> +++ b/fs/ext4/xattr.c
> @@ -2556,7 +2556,7 @@ static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
>  
>  	is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
>  	bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
> -	buffer = kmalloc(value_size, GFP_NOFS);
> +	buffer = kvmalloc(value_size, GFP_NOFS);
>  	b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
>  	if (!is || !bs || !buffer || !b_entry_name) {
>  		error = -ENOMEM;
> @@ -2608,7 +2608,7 @@ static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
>  	error = 0;
>  out:
>  	kfree(b_entry_name);
> -	kfree(buffer);
> +	kvfree(buffer);
>  	if (is)
>  		brelse(is->iloc.bh);
>  	if (bs)
> -- 
> 2.31.1
>
Theodore Ts'o Dec. 1, 2022, 4 p.m. UTC | #2 
On Thu, Dec 01, 2022 at 10:59:23PM +0800, Ye Bin wrote:
> 
> Reason is allocate 16M memory by kmalloc, but MAX_ORDER is 11, kmalloc
> can allocate maxium size memory is 4M.
> XATTR_SIZE_MAX is currently 64k, but EXT4_XATTR_SIZE_MAX is '(1 << 24)',
> so 'ext4_xattr_check_entries()' regards this length as legal. Then trigger
> warning in 'ext4_xattr_move_to_block()'.
> To solve above issue, according to Jan Kara's suggestion use kvmalloc()
> to allocate memory in ext4_xattr_move_to_block().

See my comment to the v1 version of the patch.  I suspect the real
problem is that the e_value_size is completely bogus, and we should
have checked it much earlier in the stack call trace, via a call to
xattr_check_inode().

Cheers,

					- Ted
Ye Bin Dec. 1, 2022, 4:12 p.m. UTC | #3 
On 2022/12/2 0:00, Theodore Ts'o wrote:
> On Thu, Dec 01, 2022 at 10:59:23PM +0800, Ye Bin wrote:
>> Reason is allocate 16M memory by kmalloc, but MAX_ORDER is 11, kmalloc
>> can allocate maxium size memory is 4M.
>> XATTR_SIZE_MAX is currently 64k, but EXT4_XATTR_SIZE_MAX is '(1 << 24)',
>> so 'ext4_xattr_check_entries()' regards this length as legal. Then trigger
>> warning in 'ext4_xattr_move_to_block()'.
>> To solve above issue, according to Jan Kara's suggestion use kvmalloc()
>> to allocate memory in ext4_xattr_move_to_block().
> See my comment to the v1 version of the patch.  I suspect the real
> problem is that the e_value_size is completely bogus, and we should
> have checked it much earlier in the stack call trace, via a call to
> xattr_check_inode().
Yes, Not only the e_value_size is wrong, but also the inode is wrong:
EXT4-fs: Ignoring removed nobh option
EXT4-fs error (device loop0): ext4_xattr_inode_iget:389: comm rep: inode 
#1: comm rep: iget: illegal inode #
EXT4-fs error (device loop0): ext4_xattr_inode_iget:392: comm rep: error 
while reading EA inode 1 err=-117
EXT4-fs warning (device loop0): ext4_expand_extra_isize_ea:2788: Unable 
to expand inode 15. Delete some EAs or run e2fsck.

Maybe we can do follow check  in ext4_xattr_check_entries() when 
"entry->e_value_inum != 0".
···
err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum),
                             le32_to_cpu(entry->e_hash), &ea_inode);
if (err) {
         ea_inode = NULL;
         goto out;
}

if (i_size_read(ea_inode) != size) {
         ext4_warning_inode(ea_inode,
                            "ea_inode file size=%llu entry size=%zu",
                            i_size_read(ea_inode), size);
         err = -EFSCORRUPTED;
         goto out;
}
···
>
> Cheers,
>
> 					- Ted
>
> .
>
diff mbox series

Patch

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 718ef3987f94..23cfefc6d262 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -2556,7 +2556,7 @@  static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
 
 	is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
 	bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
-	buffer = kmalloc(value_size, GFP_NOFS);
+	buffer = kvmalloc(value_size, GFP_NOFS);
 	b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
 	if (!is || !bs || !buffer || !b_entry_name) {
 		error = -ENOMEM;
@@ -2608,7 +2608,7 @@  static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
 	error = 0;
 out:
 	kfree(b_entry_name);
-	kfree(buffer);
+	kvfree(buffer);
 	if (is)
 		brelse(is->iloc.bh);
 	if (bs)