Revision 7ff57e98fb78ad94edafbdc7435f2d745e9e6bb5 authored by Fabio M. De Francesco on 23 February 2022, 10:02:52 UTC, committed by Jakub Kicinski on 24 February 2022, 17:09:33 UTC
smc_pnetid_by_table_ib() uses read_lock() and then it calls smc_pnet_apply_ib()
which, in turn, calls mutex_lock(&smc_ib_devices.mutex).
read_lock() disables preemption. Therefore, the code acquires a mutex while in
atomic context and it leads to a SAC bug.
Fix this bug by replacing the rwlock with a mutex.
Reported-and-tested-by: syzbot+4f322a6d84e991c38775@syzkaller.appspotmail.com
Fixes: 64e28b52c7a6 ("net/smc: add pnet table namespace support")
Confirmed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Link: https://lore.kernel.org/r/20220223100252.22562-1-fmdefrancesco@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
1 parent e13ad14
test_sort.c
// SPDX-License-Identifier: GPL-2.0-only
#include <kunit/test.h>
#include <linux/sort.h>
#include <linux/slab.h>
#include <linux/module.h>
/* a simple boot-time regression test */
#define TEST_LEN 1000
static int cmpint(const void *a, const void *b)
{
return *(int *)a - *(int *)b;
}
static void test_sort(struct kunit *test)
{
int *a, i, r = 1;
a = kunit_kmalloc_array(test, TEST_LEN, sizeof(*a), GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, a);
for (i = 0; i < TEST_LEN; i++) {
r = (r * 725861) % 6599;
a[i] = r;
}
sort(a, TEST_LEN, sizeof(*a), cmpint, NULL);
for (i = 0; i < TEST_LEN-1; i++)
KUNIT_ASSERT_LE(test, a[i], a[i + 1]);
}
static struct kunit_case sort_test_cases[] = {
KUNIT_CASE(test_sort),
{}
};
static struct kunit_suite sort_test_suite = {
.name = "lib_sort",
.test_cases = sort_test_cases,
};
kunit_test_suites(&sort_test_suite);
MODULE_LICENSE("GPL");
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