From d3e6952cfb7ba5f4bfa29d4803ba91f96ce1204d Mon Sep 17 00:00:00 2001 From: Vegard Nossum Date: Sat, 23 Jul 2016 07:43:50 +0200 Subject: [PATCH] net/irda: fix NULL pointer dereference on memory allocation failure I ran into this: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 2 PID: 2012 Comm: trinity-c3 Not tainted 4.7.0-rc7+ #19 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 task: ffff8800b745f2c0 ti: ffff880111740000 task.ti: ffff880111740000 RIP: 0010:[] [] irttp_connect_request+0x36/0x710 RSP: 0018:ffff880111747bb8 EFLAGS: 00010286 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000069dd8358 RDX: 0000000000000009 RSI: 0000000000000027 RDI: 0000000000000048 RBP: ffff880111747c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000069dd8358 R11: 1ffffffff0759723 R12: 0000000000000000 R13: ffff88011a7e4780 R14: 0000000000000027 R15: 0000000000000000 FS: 00007fc738404700(0000) GS:ffff88011af00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc737fdfb10 CR3: 0000000118087000 CR4: 00000000000006e0 Stack: 0000000000000200 ffff880111747bd8 ffffffff810ee611 ffff880119f1f220 ffff880119f1f4f8 ffff880119f1f4f0 ffff88011a7e4780 ffff880119f1f232 ffff880119f1f220 ffff880111747d58 ffffffff82bca542 0000000000000000 Call Trace: [] irda_connect+0x562/0x1190 [] SYSC_connect+0x202/0x2a0 [] SyS_connect+0x9/0x10 [] do_syscall_64+0x19c/0x410 [] entry_SYSCALL64_slow_path+0x25/0x25 Code: 41 89 ca 48 89 e5 41 57 41 56 41 55 41 54 41 89 d7 53 48 89 fb 48 83 c7 48 48 89 fa 41 89 f6 48 c1 ea 03 48 83 ec 20 4c 8b 65 10 <0f> b6 04 02 84 c0 74 08 84 c0 0f 8e 4c 04 00 00 80 7b 48 00 74 RIP [] irttp_connect_request+0x36/0x710 RSP ---[ end trace 4cda2588bc055b30 ]--- The problem is that irda_open_tsap() can fail and leave self->tsap = NULL, and then irttp_connect_request() almost immediately dereferences it. Cc: stable@vger.kernel.org Signed-off-by: Vegard Nossum Signed-off-by: David S. Miller --- net/irda/af_irda.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c index 923abd6b306407..8d2f7c9b491da5 100644 --- a/net/irda/af_irda.c +++ b/net/irda/af_irda.c @@ -1024,8 +1024,11 @@ static int irda_connect(struct socket *sock, struct sockaddr *uaddr, } /* Check if we have opened a local TSAP */ - if (!self->tsap) - irda_open_tsap(self, LSAP_ANY, addr->sir_name); + if (!self->tsap) { + err = irda_open_tsap(self, LSAP_ANY, addr->sir_name); + if (err) + goto out; + } /* Move to connecting socket, start sending Connect Requests */ sock->state = SS_CONNECTING;