diff mbox series

[-next,1/6] ext4: fix WARNING in ext4_expand_extra_isize_ea

Message ID	20221206015806.3420321-2-yebin@huaweicloud.com
State	New
Headers	Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; From: Ye Bin <yebin@huaweicloud.com> To: tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org Cc: linux-kernel@vger.kernel.org, jack@suse.cz, Ye Bin <yebin10@huawei.com>, syzbot+4d99a966fd74bdeeec36@syzkaller.appspotmail.com Subject: [PATCH -next 1/6] ext4: fix WARNING in ext4_expand_extra_isize_ea Date: Tue, 6 Dec 2022 09:58:01 +0800 Message-Id: <20221206015806.3420321-2-yebin@huaweicloud.com> In-Reply-To: <20221206015806.3420321-1-yebin@huaweicloud.com> References: <20221206015806.3420321-1-yebin@huaweicloud.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	Fix two issue about ext4 extended attribute \| [-next,0/6] Fix two issue about ext4 extended attribute [-next,1/6] ext4: fix WARNING in ext4_expand_extra_isize_ea [-next,2/6] ext4: add primary check extended attribute inode in ext4_xattr_check_entries() [-next,3/6] ext4: remove unnessary size check in ext4_xattr_inode_get() [-next,4/6] ext4: allocate extended attribute value in vmalloc area [-next,5/6] ext4: rename xattr_find_entry() and __xattr_check_inode() [-next,6/6] ext4: fix inode leak in 'ext4_xattr_inode_create()'

Commit Message

Ye Bin Dec. 6, 2022, 1:58 a.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.h | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

Comments

Jan Kara Dec. 6, 2022, 12:04 p.m. UTC | #1

On Tue 06-12-22 09:58:01, 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>

The changelog speak about kvmalloc() while your patch changes
EXT4_XATTR_SIZE_MAX. This needs to be fixed. If Ted is find with this
change, I have no problem with it either but I remember there were some
discussions about what EXT4_XATTR_SIZE_MAX should be when ea_inode feature
has been developed. Ted might remember.

Also the change from kmalloc() to kvmalloc() is a desirable one anyway. It
is not always easy to find physically contiguous 64k of memory so
kvmalloc() makes the allocation much more likely to succeed.

								Honza

Ye Bin Dec. 6, 2022, 1:44 p.m. UTC | #2

On 2022/12/6 20:04, Jan Kara wrote:
> On Tue 06-12-22 09:58:01, 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>
> The changelog speak about kvmalloc() while your patch changes
> EXT4_XATTR_SIZE_MAX. This needs to be fixed. If Ted is find with this
> change, I have no problem with it either but I remember there were some
> discussions about what EXT4_XATTR_SIZE_MAX should be when ea_inode feature
> has been developed. Ted might remember.

I'm sorry I forgot to modify the commit message, I will modify the 
changelog again.

> Also the change from kmalloc() to kvmalloc() is a desirable one anyway. It
> is not always easy to find physically contiguous 64k of memory so
> kvmalloc() makes the allocation much more likely to succeed.
>
> 								Honza

A later patch use kvmalloc to allocate  extended attribute value memory.

diff mbox series

Patch

diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
index 824faf0b15a8..444ee46838c3 100644
--- a/fs/ext4/xattr.h
+++ b/fs/ext4/xattr.h
@@ -71,15 +71,10 @@  struct ext4_xattr_entry {
 #define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
 
 /*
- * XATTR_SIZE_MAX is currently 64k, but for the purposes of checking
- * for file system consistency errors, we use a somewhat bigger value.
- * This allows XATTR_SIZE_MAX to grow in the future, but by using this
- * instead of INT_MAX for certain consistency checks, we don't need to
- * worry about arithmetic overflows.  (Actually XATTR_SIZE_MAX is
- * defined in include/uapi/linux/limits.h, so changing it is going
- * not going to be trivial....)
+ * Use XATTR_SIZE_MAX to checking for file system consistency errors. Extended
+ * attribute length exceed XATTR_SIZE_MAX is ilegal.
  */
-#define EXT4_XATTR_SIZE_MAX (1 << 24)
+#define EXT4_XATTR_SIZE_MAX XATTR_SIZE_MAX
 
 /*
  * The minimum size of EA value when you start storing it in an external inode