From 3f2d67b6bd24c615cfe3a6d793613bb2838dd9b9 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Mon, 11 Jun 2018 07:12:12 -0700 Subject: [PATCH] net/ipv6: Ensure cfg is properly initialized in ipv6_create_tempaddr Valdis reported a BUG in ipv6_add_addr: [ 1820.832682] BUG: unable to handle kernel NULL pointer dereference at 0000000000000209 [ 1820.832728] RIP: 0010:ipv6_add_addr+0x280/0xd10 [ 1820.832732] Code: 49 8b 1f 0f 84 6a 0a 00 00 48 85 db 0f 84 4e 0a 00 00 48 8b 03 48 8b 53 08 49 89 45 00 49 8b 47 10 49 89 55 08 48 85 c0 74 15 <48> 8b 50 08 48 8b 00 49 89 95 b8 01 00 00 49 89 85 b0 01 00 00 4c [ 1820.832847] RSP: 0018:ffffaa07c2fd7880 EFLAGS: 00010202 [ 1820.832853] RAX: 0000000000000201 RBX: ffffaa07c2fd79b0 RCX: 0000000000000000 [ 1820.832858] RDX: a4cfbfba2cbfa64c RSI: 0000000000000000 RDI: ffffffff8a8e9fa0 [ 1820.832862] RBP: ffffaa07c2fd7920 R08: 000000000000017a R09: ffffffff8a555300 [ 1820.832866] R10: 0000000000000000 R11: 0000000000000000 R12: ffff888d18e71c00 [ 1820.832871] R13: ffff888d0a9b1200 R14: 0000000000000000 R15: ffffaa07c2fd7980 [ 1820.832876] FS: 00007faa51bdb800(0000) GS:ffff888d1d400000(0000) knlGS:0000000000000000 [ 1820.832880] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1820.832885] CR2: 0000000000000209 CR3: 000000021e8f8001 CR4: 00000000001606e0 [ 1820.832888] Call Trace: [ 1820.832898] ? __local_bh_enable_ip+0x119/0x260 [ 1820.832904] ? ipv6_create_tempaddr+0x259/0x5a0 [ 1820.832912] ? __local_bh_enable_ip+0x139/0x260 [ 1820.832921] ipv6_create_tempaddr+0x2da/0x5a0 [ 1820.832926] ? ipv6_create_tempaddr+0x2da/0x5a0 [ 1820.832941] manage_tempaddrs+0x1a5/0x240 [ 1820.832951] inet6_addr_del+0x20b/0x3b0 [ 1820.832959] ? nla_parse+0xce/0x1e0 [ 1820.832968] inet6_rtm_deladdr+0xd9/0x210 [ 1820.832981] rtnetlink_rcv_msg+0x1d4/0x5f0 Looking at the code I found 1 element (peer_pfx) of the newly introduced ifa6_config struct that is not initialized. Use a memset rather than hard coding an init for each struct element. Reported-by: Valdis Kletnieks Fixes: e6464b8c63619 ("net/ipv6: Convert ipv6_add_addr to struct ifa6_config") Signed-off-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 89019bf59f46..c134286d6a41 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -1324,6 +1324,7 @@ retry: } } + memset(&cfg, 0, sizeof(cfg)); cfg.valid_lft = min_t(__u32, ifp->valid_lft, idev->cnf.temp_valid_lft + age); cfg.preferred_lft = cnf_temp_preferred_lft + age - idev->desync_factor; @@ -1357,7 +1358,6 @@ retry: cfg.pfx = &addr; cfg.scope = ipv6_addr_scope(cfg.pfx); - cfg.rt_priority = 0; ift = ipv6_add_addr(idev, &cfg, block, NULL); if (IS_ERR(ift)) { -- 2.39.5