From: Jitendra Sharma <shajit@codeaurora.org>
To: keescook@chromium.org, mcgrof@kernel.org
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-arm-msm@vger.kernel.org
Subject: fs/proc: Crash observed in next_tgid (fs/proc/base.c)
Date: Mon, 15 Apr 2019 18:28:25 +0530 [thread overview]
Message-ID: <b5b9df7b-324c-8286-3a7c-e7812511772d@codeaurora.org> (raw)
Hi Kees Cook/Luis,
We are observing one kernel crash in next_tgid function through
getdents64 path. Call stack is as shown below:
-000|has_group_leader_pid(inline)
-000|next_tgid(
| [X20] ns = 0xFFFFFF87CABB1AC0,
| [locdesc] iter = (
| [locdesc] tgid = 424,
| [locdesc] task = ?))
| [X21] p = 0xFFFFFFD0FFFFF948
| [X21] task = 0xFFFFFFD0FFFFF948
-001|proc_pid_readdir(
| [X20] file = 0xFFFFFFD1AC60FC40,
| [X19] ctx = 0xFFFFFF8027363E40)
| [X21] ns = 0xFFFFFF87CABB1AC0
-002|proc_root_readdir(
| [X20] file = 0xFFFFFFD1AC60FC40,
| [X19] ctx = 0xFFFFFF8027363E40)
-003|iterate_dir(
| [X19] file = 0xFFFFFFD1AC60FC40,
| [X22] ctx = 0xFFFFFF8027363E40)
| [X23] inode = 0xFFFFFFD1F20246D0
-004|SYSC_getdents64(inline)
-004|sys_getdents64(
| ?,
| ?,
| [X19] count = 4200)
| [X19] count = 4200
| [X20] f = ([X20] file = 0xAC60FC43AC60FC40, [X20] flags = 1207898624)
| [X0] error = -1720
-005|el0_svc_naked(asm)
-->|exception
-006|NUX:0x78C5AD7D38(asm)
---|end of frame
From this call stack,task: 0xFFFFFFD0FFFFF948, seems to be invalid.
As(from ramdumps) it doesn't have any valid fields. And while trying to
access the fields of this task struct in has_group_leader_pid, abort is
happening.
From the dumps, its not clear why the task struct is coming to be some
invalid (Possibly task has already exited). This issue is observed
during normal monkey testing for long hours.
Could you please provide some pointers which could help in debugging
this issue further.
Thanks,
Jitendra
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
next reply other threads:[~2019-04-15 12:58 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-15 12:58 Jitendra Sharma [this message]
2019-04-17 3:38 ` fs/proc: Crash observed in next_tgid (fs/proc/base.c) Kees Cook
2019-04-17 11:21 ` Oleg Nesterov
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