From 0f9aee0cb9da7db7d96f63cfa2dc5e4f1bffeb87 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Mon, 23 Dec 2019 07:54:22 +0000 Subject: powerpc/mm: Don't log user reads to 0xffffffff Running vdsotest leaves many times the following log: [ 79.629901] vdsotest[396]: User access of kernel address (ffffffff) - exploit attempt? (uid: 0) A pointer set to (-1) is likely a programming error similar to a NULL pointer and is not worth logging as an exploit attempt. Don't log user accesses to 0xffffffff. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/0728849e826ba16f1fbd6fa7f5c6cc87bd64e097.1577087627.git.christophe.leroy@c-s.fr --- arch/powerpc/mm/fault.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/powerpc/mm/fault.c') diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 9e119f98a725..7534ee5bf9b2 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -350,6 +350,9 @@ static void sanity_check_fault(bool is_write, bool is_user, * Userspace trying to access kernel address, we get PROTFAULT for that. */ if (is_user && address >= TASK_SIZE) { + if ((long)address == -1) + return; + pr_crit_ratelimited("%s[%d]: User access of kernel address (%lx) - exploit attempt? (uid: %d)\n", current->comm, current->pid, address, from_kuid(&init_user_ns, current_uid())); -- cgit v1.2.3-59-g8ed1b