Messages in this thread Patch in this message | | | From | Nikita Kiryushin <> | Subject | [PATCH] rcu: Fix buffer overlow in print_cpu_stall_info() | Date | Thu, 28 Mar 2024 21:19:14 +0300 |
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rcuc info output in print_cpu_stall_info() contains posiible buffer overflow in the case of huge jiffies difference. The situation seems improbable, but, buffer overflow, still. Also, unsigned jiffies difference printed as (signed) %ld (which can be a bad format, if the values are huge).
Change sprintf to snprintf and change %ld to %lu in format.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 245a62982502 ("rcu: Dump rcuc kthread status for CPUs not reporting quiescent state") Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru> --- kernel/rcu/tree_stall.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index 5d666428546b..d4542c6e7c60 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -504,7 +504,7 @@ static void print_cpu_stall_info(int cpu) rcu_dynticks_in_eqs(rcu_dynticks_snap(cpu)); rcuc_starved = rcu_is_rcuc_kthread_starving(rdp, &j); if (rcuc_starved) - sprintf(buf, " rcuc=%ld jiffies(starved)", j); + snprintf(buf, sizeof(buf), " rcuc=%lu jiffies(starved)", j); pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%04x/%ld/%#lx softirq=%u/%u fqs=%ld%s%s\n", cpu, "O."[!!cpu_online(cpu)], -- 2.34.1
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