From: Sasha Levin Date: Sat, 30 Jun 2012 09:56:47 +0000 (+0200) Subject: NFC: Prevent NULL deref when getting socket name X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=147f20e316f3949f3f5ffe6c8658e9fe1c6ceb23;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git NFC: Prevent NULL deref when getting socket name llcp_sock_getname can be called without a device attached to the nfc_llcp_sock. This would lead to the following BUG: [ 362.341807] BUG: unable to handle kernel NULL pointer dereference at (null) [ 362.341815] IP: [] llcp_sock_getname+0x75/0xc0 [ 362.341818] PGD 31b35067 PUD 30631067 PMD 0 [ 362.341821] Oops: 0000 [#627] PREEMPT SMP DEBUG_PAGEALLOC [ 362.341826] CPU 3 [ 362.341827] Pid: 7816, comm: trinity-child55 Tainted: G D W 3.5.0-rc4-next-20120628-sasha-00005-g9f23eb7 #479 [ 362.341831] RIP: 0010:[] [] llcp_sock_getname+0x75/0xc0 [ 362.341832] RSP: 0018:ffff8800304fde88 EFLAGS: 00010286 [ 362.341834] RAX: 0000000000000000 RBX: ffff880033cb8000 RCX: 0000000000000001 [ 362.341835] RDX: ffff8800304fdec4 RSI: ffff8800304fdec8 RDI: ffff8800304fdeda [ 362.341836] RBP: ffff8800304fdea8 R08: 7ebcebcb772b7ffb R09: 5fbfcb9c35bdfd53 [ 362.341838] R10: 4220020c54326244 R11: 0000000000000246 R12: ffff8800304fdec8 [ 362.341839] R13: ffff8800304fdec4 R14: ffff8800304fdec8 R15: 0000000000000044 [ 362.341841] FS: 00007effa376e700(0000) GS:ffff880035a00000(0000) knlGS:0000000000000000 [ 362.341843] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 362.341844] CR2: 0000000000000000 CR3: 0000000030438000 CR4: 00000000000406e0 [ 362.341851] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 362.341856] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 362.341858] Process trinity-child55 (pid: 7816, threadinfo ffff8800304fc000, task ffff880031270000) [ 362.341858] Stack: [ 362.341862] ffff8800304fdea8 ffff880035156780 0000000000000000 0000000000001000 [ 362.341865] ffff8800304fdf78 ffffffff83183b40 00000000304fdec8 0000006000000000 [ 362.341868] ffff8800304f0027 ffffffff83729649 ffff8800304fdee8 ffff8800304fdf48 [ 362.341869] Call Trace: [ 362.341874] [] sys_getpeername+0xa0/0x110 [ 362.341877] [] ? _raw_spin_unlock_irq+0x59/0x80 [ 362.341882] [] ? do_setitimer+0x23b/0x290 [ 362.341886] [] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 362.341889] [] system_call_fastpath+0x16/0x1b [ 362.341921] Code: 84 00 00 00 00 00 b8 b3 ff ff ff 48 85 db 74 54 66 41 c7 04 24 27 00 49 8d 7c 24 12 41 c7 45 00 60 00 00 00 48 8b 83 28 05 00 00 <8b> 00 41 89 44 24 04 0f b6 83 41 05 00 00 41 88 44 24 10 0f b6 [ 362.341924] RIP [] llcp_sock_getname+0x75/0xc0 [ 362.341925] RSP [ 362.341926] CR2: 0000000000000000 [ 362.341928] ---[ end trace 6d450e935ee18bf3 ]--- Signed-off-by: Sasha Levin Signed-off-by: John W. Linville --- diff --git a/net/nfc/llcp/sock.c b/net/nfc/llcp/sock.c index 17a707db40eb..e06d458fc719 100644 --- a/net/nfc/llcp/sock.c +++ b/net/nfc/llcp/sock.c @@ -292,7 +292,7 @@ static int llcp_sock_getname(struct socket *sock, struct sockaddr *addr, pr_debug("%p\n", sk); - if (llcp_sock == NULL) + if (llcp_sock == NULL || llcp_sock->dev == NULL) return -EBADFD; addr->sa_family = AF_NFC;