[LU-12604] Lustre mdt_file_secctx_unpack() bug

• Type: Bug
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.13.0, Lustre 2.12.3
• Severity: 3
• Assignee: Sebastien Buisson
• Reporter: Alibaba Cloud (Inactive)

Description

In the latest version of lustre file system, mdt module has a out-of-access bug due to the lack of validation for specific fields of packets sent by client.

The kernel panic:

 

[  207.996447] Call Trace:
[  207.998174]  [<ffffffffc0fc12d6>] mdt_file_secctx_unpack+0xb6/0x140 [mdt]
[  208.000279]  [<ffffffffc0fc6ecc>] mdt_open_unpack+0x19c/0x410 [mdt]
[  208.002318]  [<ffffffffc0fc71eb>] mdt_reint_unpack+0xab/0x210 [mdt]
[  208.004342]  [<ffffffffc0fb0d23>] mdt_reint_internal+0x43/0xb90 [mdt]
[  208.006379]  [<ffffffffc0fbd8e0>] ? mdt_intent_fixup_resent+0x160/0x220 [mdt]
[  208.008481]  [<ffffffffc0fbda22>] mdt_intent_open+0x82/0x3a0 [mdt]
[  208.010505]  [<ffffffffc0697b49>] ? lprocfs_counter_add+0xf9/0x160 [obdclass]
[  208.012619]  [<ffffffffc0fbb9e4>] mdt_intent_policy+0x2d4/0xdd0 [mdt]
[  208.014675]  [<ffffffffc0fbd9a0>] ? mdt_intent_fixup_resent+0x220/0x220 [mdt]
[  208.016810]  [<ffffffffc08a3c66>] ldlm_lock_enqueue+0x356/0xa20 [ptlrpc]
[  208.018833]  [<ffffffffc052f3d3>] ? cfs_hash_bd_add_locked+0x63/0x80 [libcfs]
[  208.020881]  [<ffffffffc053296e>] ? cfs_hash_add+0xbe/0x1a0 [libcfs]
[  208.022874]  [<ffffffffc08cc587>] ldlm_handle_enqueue0+0xa47/0x15a0 [ptlrpc]
[  208.024948]  [<ffffffffc08f4520>] ? lustre_swab_ldlm_lock_desc+0x30/0x30 [ptlrpc]
[  208.027041]  [<ffffffffc0955082>] tgt_enqueue+0x62/0x210 [ptlrpc]
[  208.028973]  [<ffffffffc095b2ca>] tgt_request_handle+0x91a/0x15c0 [ptlrpc]
[  208.030903]  [<ffffffffc052bfa7>] ? libcfs_debug_msg+0x57/0x80 [libcfs]
[  208.032796]  [<ffffffffc08fe88e>] ptlrpc_server_handle_request+0x24e/0xab0 [ptlrpc]
[  208.034745]  [<ffffffff8eccbadb>] ? __wake_up_common+0x5b/0x90
[  208.036513]  [<ffffffffc0902384>] ptlrpc_main+0xbb4/0x20f0 [ptlrpc]
[  208.038274]  [<ffffffff8ecd08c0>] ? finish_task_switch+0x50/0x1c0
[  208.040036]  [<ffffffffc09017d0>] ? ptlrpc_register_service+0xfa0/0xfa0 [ptlrpc]
[  208.041892]  [<ffffffff8ecc1c71>] kthread+0xd1/0xe0
[  208.043535]  [<ffffffff8ecc1ba0>] ? insert_kthread_work+0x40/0x40
[  208.045284]  [<ffffffff8f375c1d>] ret_from_fork_nospec_begin+0x7/0x21
[  208.047012]  [<ffffffff8ecc1ba0>] ? insert_kthread_work+0x40/0x40

In function mdt_file_secctx_unpack(), it don't check the value of name_size derived from req_capsule_get_size(), and cause a out-of-access bug in strnlen.

 

Issue Links

• is related to: LU-12605 Lustre target_handle_connect() bug

Comments

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/35868/
Subject: LU-12604 mdt: check field size of sec context name
Project: fs/lustre-release
Branch: b2_12
Current Patch Set:
Commit: 92d09db94d725bb36a81bda6219c4ec9dfd17d0a

[Gerrit Updater]

Minh Diep ([e-mail]) uploaded a new patch: https://review.whamcloud.com/35868
Subject: LU-12604 mdt: check field size of sec context name
Project: fs/lustre-release
Branch: b2_12
Current Patch Set: 1
Commit: b3a5740be9e604a9f0e25d30655bab59d6022020

[Peter Jones]

Landed for 2.13

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/35655/
Subject: LU-12604 mdt: check field size of sec context name
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 384cd84489c9a7aa3145560002eb7a053cf4b2db

[Gerrit Updater]

Sebastien Buisson ([e-mail]) uploaded a new patch: https://review.whamcloud.com/35655
Subject: LU-12604 mdt: check field size of sec context name
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: e1ef6df469e4a72bb45ba1e1087739d87f957d0d

[Sebastien Buisson]

I am looking into this.

In the meantime, do you have more information coming along with the stack trace? For instance, the exact error message? More importantly, are you able to analyze the crash dump and retrieve the content of the name_size variable? I am wondering how this got corrupted.

Thanks.