From 54dc77d974a50147d6639dac6f59cb2c29207161 Mon Sep 17 00:00:00 2001 From: Richard Guy Briggs Date: Thu, 18 Dec 2014 23:09:27 -0500 Subject: [PATCH] audit: use supplied gfp_mask from audit_buffer in kauditd_send_multicast_skb Eric Paris explains: Since kauditd_send_multicast_skb() gets called in audit_log_end(), which can come from any context (aka even a sleeping context) GFP_KERNEL can't be used. Since the audit_buffer knows what context it should use, pass that down and use that. See: https://lkml.org/lkml/2014/12/16/542 BUG: sleeping function called from invalid context at mm/slab.c:2849 in_atomic(): 1, irqs_disabled(): 0, pid: 885, name: sulogin 2 locks held by sulogin/885: #0: (&sig->cred_guard_mutex){+.+.+.}, at: [] prepare_bprm_creds+0x28/0x8b #1: (tty_files_lock){+.+.+.}, at: [] selinux_bprm_committing_creds+0x55/0x22b CPU: 1 PID: 885 Comm: sulogin Not tainted 3.18.0-next-20141216 #30 Hardware name: Dell Inc. Latitude E6530/07Y85M, BIOS A15 06/20/2014 ffff880223744f10 ffff88022410f9b8 ffffffff916ba529 0000000000000375 ffff880223744f10 ffff88022410f9e8 ffffffff91063185 0000000000000006 0000000000000000 0000000000000000 0000000000000000 ffff88022410fa38 Call Trace: [] dump_stack+0x50/0xa8 [] ___might_sleep+0x1b6/0x1be [] __might_sleep+0x119/0x128 [] cache_alloc_debugcheck_before.isra.45+0x1d/0x1f [] kmem_cache_alloc+0x43/0x1c9 [] __alloc_skb+0x42/0x1a3 [] skb_copy+0x3e/0xa3 [] audit_log_end+0x83/0x100 [] ? avc_audit_pre_callback+0x103/0x103 [] common_lsm_audit+0x441/0x450 [] slow_avc_audit+0x63/0x67 [] avc_has_perm+0xca/0xe3 [] inode_has_perm+0x5a/0x65 [] selinux_bprm_committing_creds+0x98/0x22b [] security_bprm_committing_creds+0xe/0x10 [] install_exec_creds+0xe/0x79 [] load_elf_binary+0xe36/0x10d7 [] search_binary_handler+0x81/0x18c [] do_execveat_common.isra.31+0x4e3/0x7b7 [] do_execve+0x1f/0x21 [] SyS_execve+0x25/0x29 [] stub_execve+0x69/0xa0 Cc: stable@vger.kernel.org #v3.16-rc1 Reported-by: Valdis Kletnieks Signed-off-by: Richard Guy Briggs Tested-by: Valdis Kletnieks Signed-off-by: Paul Moore --- kernel/audit.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/audit.c b/kernel/audit.c index f3a981db91ff..c7e097a0d7af 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -429,7 +429,7 @@ static void kauditd_send_skb(struct sk_buff *skb) * This function doesn't consume an skb as might be expected since it has to * copy it anyways. */ -static void kauditd_send_multicast_skb(struct sk_buff *skb) +static void kauditd_send_multicast_skb(struct sk_buff *skb, gfp_t gfp_mask) { struct sk_buff *copy; struct audit_net *aunet = net_generic(&init_net, audit_net_id); @@ -448,11 +448,11 @@ static void kauditd_send_multicast_skb(struct sk_buff *skb) * no reason for new multicast clients to continue with this * non-compliance. */ - copy = skb_copy(skb, GFP_KERNEL); + copy = skb_copy(skb, gfp_mask); if (!copy) return; - nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL); + nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, gfp_mask); } /* @@ -1949,7 +1949,7 @@ void audit_log_end(struct audit_buffer *ab) struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); nlh->nlmsg_len = ab->skb->len; - kauditd_send_multicast_skb(ab->skb); + kauditd_send_multicast_skb(ab->skb, ab->gfp_mask); /* * The original kaudit unicast socket sends up messages with -- 2.20.1