* Re: [PATCH net 2/2] ipv4: make exception cache less predictible
[not found] <20210829221615.2057201-3-eric.dumazet@gmail.com>
@ 2021-08-30 11:34 ` Dan Carpenter
0 siblings, 0 replies; only message in thread
From: Dan Carpenter @ 2021-08-30 11:34 UTC (permalink / raw)
To: kbuild, Eric Dumazet, kernel-janitors; +Cc: lkp, kbuild-all
[ I trimmed the CC list because this is probably a false positive and
netdev hates static checker warnings. - dan ]
Hi Eric,
url: https://github.com/0day-ci/linux/commits/Eric-Dumazet/inet-make-exception-handling-less-predictible/20210830-061726
base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git 57f780f1c43362b86fd23d20bd940e2468237716
config: x86_64-randconfig-m001-20210829 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
smatch warnings:
net/ipv4/route.c:606 fnhe_remove_oldest() error: potentially dereferencing uninitialized 'oldest_p'.
vim +/oldest_p +606 net/ipv4/route.c
adf305d00ec06cb Eric Dumazet 2021-08-29 589 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash)
4895c771c7f006b David S. Miller 2012-07-17 590 {
adf305d00ec06cb Eric Dumazet 2021-08-29 591 struct fib_nh_exception __rcu **fnhe_p, **oldest_p;
adf305d00ec06cb Eric Dumazet 2021-08-29 592 struct fib_nh_exception *fnhe, *oldest = NULL;
4895c771c7f006b David S. Miller 2012-07-17 593
adf305d00ec06cb Eric Dumazet 2021-08-29 594 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) {
adf305d00ec06cb Eric Dumazet 2021-08-29 595 fnhe = rcu_dereference_protected(*fnhe_p,
adf305d00ec06cb Eric Dumazet 2021-08-29 596 lockdep_is_held(&fnhe_lock));
adf305d00ec06cb Eric Dumazet 2021-08-29 597 if (!fnhe)
adf305d00ec06cb Eric Dumazet 2021-08-29 598 break;
Smatch is complaining that this could break on the first iteration
through the loop...
adf305d00ec06cb Eric Dumazet 2021-08-29 599 if (!oldest ||
adf305d00ec06cb Eric Dumazet 2021-08-29 600 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) {
4895c771c7f006b David S. Miller 2012-07-17 601 oldest = fnhe;
adf305d00ec06cb Eric Dumazet 2021-08-29 602 oldest_p = fnhe_p;
adf305d00ec06cb Eric Dumazet 2021-08-29 603 }
4895c771c7f006b David S. Miller 2012-07-17 604 }
2ffae99d1fac272 Timo Teräs 2013-06-27 605 fnhe_flush_routes(oldest);
adf305d00ec06cb Eric Dumazet 2021-08-29 @606 *oldest_p = oldest->fnhe_next;
adf305d00ec06cb Eric Dumazet 2021-08-29 607 kfree_rcu(oldest, rcu);
4895c771c7f006b David S. Miller 2012-07-17 608 }
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
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