From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: akpm@linux-foundation.org, ishkamiel@gmail.com,
rostedt@goodmis.org, dvyukov@google.com,
andrea.parri@amarulasolutions.com, anders.roxell@linaro.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
elena.reshetova@intel.com, andreyknvl@google.com
Cc: linux-kernel@vger.kernel.org
Subject: [BUG] kernel: kcov: a possible sleep-in-atomic-context bug in kcov_ioctl()
Date: Tue, 17 Dec 2019 20:56:53 +0800 [thread overview]
Message-ID: <3c4608bc-9c84-d79b-de76-b1a1a2a4fb6d@gmail.com> (raw)
The kernel may sleep while holding a spinlock.
The function call path (from bottom to top) in Linux 4.19 is:
kernel/kcov.c, 237:
vfree in kcov_put
kernel/kcov.c, 413:
kcov_put in kcov_ioctl_locked
kernel/kcov.c, 427:
kcov_ioctl_locked in kcov_ioctl
kernel/kcov.c, 426:
spin_lock in kcov_ioctl
vfree() can sleep at runtime.
I am not sure how to properly fix this possible bug, so I only report it.
A possible way is to replace vfree() with kfree(), and replace related
calls to vmalloc() with kmalloc().
This bug is found by a static analysis tool STCheck written by myself.
Best wishes,
Jia-Ju Bai
next reply other threads:[~2019-12-17 12:56 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-17 12:56 Jia-Ju Bai [this message]
2019-12-17 13:02 ` Dmitry Vyukov
2019-12-17 13:11 ` Jia-Ju Bai
2019-12-17 13:13 ` Dmitry Vyukov
2019-12-17 13:17 ` Jia-Ju Bai
-- strict thread matches above, loose matches on Subject: below --
2018-06-21 3:20 Jia-Ju Bai
2018-06-21 3:43 ` Al Viro
2018-06-21 3:50 ` Jia-Ju Bai
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