| Message ID | 20220509143749.6416-1-eric.dumazet@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [stable-v5.10] net: igmp: respect RCU rules in ip_mc_source() and ip_mc_msfilter() | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Guessing tree name failed - patch did not apply |
On Mon, May 09, 2022 at 07:37:49AM -0700, Eric Dumazet wrote: > From: Eric Dumazet <edumazet@google.com> > > commit dba5bdd57bea587ea4f0b79b03c71135f84a7e8b upstream. > > syzbot reported an UAF in ip_mc_sf_allow() [1] > > Whenever RCU protected list replaces an object, > the pointer to the new object needs to be updated > _before_ the call to kfree_rcu() or call_rcu() > > Because kfree_rcu(ptr, rcu) got support for NULL ptr > only recently in commit 12edff045bc6 ("rcu: Make kfree_rcu() > ignore NULL pointers"), I chose to use the conditional > to make sure stable backports won't miss this detail. > > if (psl) > kfree_rcu(psl, rcu); > > net/ipv6/mcast.c has similar issues, addressed in a separate patch. > > [1] > BUG: KASAN: use-after-free in ip_mc_sf_allow+0x6bb/0x6d0 net/ipv4/igmp.c:2655 > Read of size 4 at addr ffff88807d37b904 by task syz-executor.5/908 > > CPU: 0 PID: 908 Comm: syz-executor.5 Not tainted 5.18.0-rc4-syzkaller-00064-g8f4dd16603ce #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 > print_address_description.constprop.0.cold+0xeb/0x467 mm/kasan/report.c:313 > print_report mm/kasan/report.c:429 [inline] > kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 > ip_mc_sf_allow+0x6bb/0x6d0 net/ipv4/igmp.c:2655 > raw_v4_input net/ipv4/raw.c:190 [inline] > raw_local_deliver+0x4d1/0xbe0 net/ipv4/raw.c:218 > ip_protocol_deliver_rcu+0xcf/0xb30 net/ipv4/ip_input.c:193 > ip_local_deliver_finish+0x2ee/0x4c0 net/ipv4/ip_input.c:233 > NF_HOOK include/linux/netfilter.h:307 [inline] > NF_HOOK include/linux/netfilter.h:301 [inline] > ip_local_deliver+0x1b3/0x200 net/ipv4/ip_input.c:254 > dst_input include/net/dst.h:461 [inline] > ip_rcv_finish+0x1cb/0x2f0 net/ipv4/ip_input.c:437 > NF_HOOK include/linux/netfilter.h:307 [inline] > NF_HOOK include/linux/netfilter.h:301 [inline] > ip_rcv+0xaa/0xd0 net/ipv4/ip_input.c:556 > __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5405 > __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5519 > netif_receive_skb_internal net/core/dev.c:5605 [inline] > netif_receive_skb+0x13e/0x8e0 net/core/dev.c:5664 > tun_rx_batched.isra.0+0x460/0x720 drivers/net/tun.c:1534 > tun_get_user+0x28b7/0x3e30 drivers/net/tun.c:1985 > tun_chr_write_iter+0xdb/0x200 drivers/net/tun.c:2015 > call_write_iter include/linux/fs.h:2050 [inline] > new_sync_write+0x38a/0x560 fs/read_write.c:504 > vfs_write+0x7c0/0xac0 fs/read_write.c:591 > ksys_write+0x127/0x250 fs/read_write.c:644 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x44/0xae > RIP: 0033:0x7f3f12c3bbff > Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 cc fd ff ff 48 > RSP: 002b:00007f3f13ea9130 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 > RAX: ffffffffffffffda RBX: 00007f3f12d9bf60 RCX: 00007f3f12c3bbff > RDX: 0000000000000036 RSI: 0000000020002ac0 RDI: 00000000000000c8 > RBP: 00007f3f12ce308d R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000036 R11: 0000000000000293 R12: 0000000000000000 > R13: 00007fffb68dd79f R14: 00007f3f13ea9300 R15: 0000000000022000 > </TASK> > > Allocated by task 908: > kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 > kasan_set_track mm/kasan/common.c:45 [inline] > set_alloc_info mm/kasan/common.c:436 [inline] > ____kasan_kmalloc mm/kasan/common.c:515 [inline] > ____kasan_kmalloc mm/kasan/common.c:474 [inline] > __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:524 > kasan_kmalloc include/linux/kasan.h:234 [inline] > __do_kmalloc mm/slab.c:3710 [inline] > __kmalloc+0x209/0x4d0 mm/slab.c:3719 > kmalloc include/linux/slab.h:586 [inline] > sock_kmalloc net/core/sock.c:2501 [inline] > sock_kmalloc+0xb5/0x100 net/core/sock.c:2492 > ip_mc_source+0xba2/0x1100 net/ipv4/igmp.c:2392 > do_ip_setsockopt net/ipv4/ip_sockglue.c:1296 [inline] > ip_setsockopt+0x2312/0x3ab0 net/ipv4/ip_sockglue.c:1432 > raw_setsockopt+0x274/0x2c0 net/ipv4/raw.c:861 > __sys_setsockopt+0x2db/0x6a0 net/socket.c:2180 > __do_sys_setsockopt net/socket.c:2191 [inline] > __se_sys_setsockopt net/socket.c:2188 [inline] > __x64_sys_setsockopt+0xba/0x150 net/socket.c:2188 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > Freed by task 753: > kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 > kasan_set_track+0x21/0x30 mm/kasan/common.c:45 > kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 > ____kasan_slab_free mm/kasan/common.c:366 [inline] > ____kasan_slab_free+0x13d/0x180 mm/kasan/common.c:328 > kasan_slab_free include/linux/kasan.h:200 [inline] > __cache_free mm/slab.c:3439 [inline] > kmem_cache_free_bulk+0x69/0x460 mm/slab.c:3774 > kfree_bulk include/linux/slab.h:437 [inline] > kfree_rcu_work+0x51c/0xa10 kernel/rcu/tree.c:3318 > process_one_work+0x996/0x1610 kernel/workqueue.c:2289 > worker_thread+0x665/0x1080 kernel/workqueue.c:2436 > kthread+0x2e9/0x3a0 kernel/kthread.c:376 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 > > Last potentially related work creation: > kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 > __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348 > kvfree_call_rcu+0x74/0x990 kernel/rcu/tree.c:3595 > ip_mc_msfilter+0x712/0xb60 net/ipv4/igmp.c:2510 > do_ip_setsockopt net/ipv4/ip_sockglue.c:1257 [inline] > ip_setsockopt+0x32e1/0x3ab0 net/ipv4/ip_sockglue.c:1432 > raw_setsockopt+0x274/0x2c0 net/ipv4/raw.c:861 > __sys_setsockopt+0x2db/0x6a0 net/socket.c:2180 > __do_sys_setsockopt net/socket.c:2191 [inline] > __se_sys_setsockopt net/socket.c:2188 [inline] > __x64_sys_setsockopt+0xba/0x150 net/socket.c:2188 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > Second to last potentially related work creation: > kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 > __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348 > call_rcu+0x99/0x790 kernel/rcu/tree.c:3074 > mpls_dev_notify+0x552/0x8a0 net/mpls/af_mpls.c:1656 > notifier_call_chain+0xb5/0x200 kernel/notifier.c:84 > call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1938 > call_netdevice_notifiers_extack net/core/dev.c:1976 [inline] > call_netdevice_notifiers net/core/dev.c:1990 [inline] > unregister_netdevice_many+0x92e/0x1890 net/core/dev.c:10751 > default_device_exit_batch+0x449/0x590 net/core/dev.c:11245 > ops_exit_list+0x125/0x170 net/core/net_namespace.c:167 > cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594 > process_one_work+0x996/0x1610 kernel/workqueue.c:2289 > worker_thread+0x665/0x1080 kernel/workqueue.c:2436 > kthread+0x2e9/0x3a0 kernel/kthread.c:376 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 > > The buggy address belongs to the object at ffff88807d37b900 > which belongs to the cache kmalloc-64 of size 64 > The buggy address is located 4 bytes inside of > 64-byte region [ffff88807d37b900, ffff88807d37b940) > > The buggy address belongs to the physical page: > page:ffffea0001f4dec0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807d37b180 pfn:0x7d37b > flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) > raw: 00fff00000000200 ffff888010c41340 ffffea0001c795c8 ffff888010c40200 > raw: ffff88807d37b180 ffff88807d37b000 000000010000001f 0000000000000000 > page dumped because: kasan: bad access detected > page_owner tracks the page as allocated > page last allocated via order 0, migratetype Unmovable, gfp_mask 0x342040(__GFP_IO|__GFP_NOWARN|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 2963, tgid 2963 (udevd), ts 139732238007, free_ts 139730893262 > prep_new_page mm/page_alloc.c:2441 [inline] > get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182 > __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408 > __alloc_pages_node include/linux/gfp.h:587 [inline] > kmem_getpages mm/slab.c:1378 [inline] > cache_grow_begin+0x75/0x350 mm/slab.c:2584 > cache_alloc_refill+0x27f/0x380 mm/slab.c:2957 > ____cache_alloc mm/slab.c:3040 [inline] > ____cache_alloc mm/slab.c:3023 [inline] > __do_cache_alloc mm/slab.c:3267 [inline] > slab_alloc mm/slab.c:3309 [inline] > __do_kmalloc mm/slab.c:3708 [inline] > __kmalloc+0x3b3/0x4d0 mm/slab.c:3719 > kmalloc include/linux/slab.h:586 [inline] > kzalloc include/linux/slab.h:714 [inline] > tomoyo_encode2.part.0+0xe9/0x3a0 security/tomoyo/realpath.c:45 > tomoyo_encode2 security/tomoyo/realpath.c:31 [inline] > tomoyo_encode+0x28/0x50 security/tomoyo/realpath.c:80 > tomoyo_realpath_from_path+0x186/0x620 security/tomoyo/realpath.c:288 > tomoyo_get_realpath security/tomoyo/file.c:151 [inline] > tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822 > security_inode_getattr+0xcf/0x140 security/security.c:1350 > vfs_getattr fs/stat.c:157 [inline] > vfs_statx+0x16a/0x390 fs/stat.c:232 > vfs_fstatat+0x8c/0xb0 fs/stat.c:255 > __do_sys_newfstatat+0x91/0x110 fs/stat.c:425 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x44/0xae > page last free stack trace: > reset_page_owner include/linux/page_owner.h:24 [inline] > free_pages_prepare mm/page_alloc.c:1356 [inline] > free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1406 > free_unref_page_prepare mm/page_alloc.c:3328 [inline] > free_unref_page+0x19/0x6a0 mm/page_alloc.c:3423 > __vunmap+0x85d/0xd30 mm/vmalloc.c:2667 > __vfree+0x3c/0xd0 mm/vmalloc.c:2715 > vfree+0x5a/0x90 mm/vmalloc.c:2746 > __do_replace+0x16b/0x890 net/ipv6/netfilter/ip6_tables.c:1117 > do_replace net/ipv6/netfilter/ip6_tables.c:1157 [inline] > do_ip6t_set_ctl+0x90d/0xb90 net/ipv6/netfilter/ip6_tables.c:1639 > nf_setsockopt+0x83/0xe0 net/netfilter/nf_sockopt.c:101 > ipv6_setsockopt+0x122/0x180 net/ipv6/ipv6_sockglue.c:1026 > tcp_setsockopt+0x136/0x2520 net/ipv4/tcp.c:3696 > __sys_setsockopt+0x2db/0x6a0 net/socket.c:2180 > __do_sys_setsockopt net/socket.c:2191 [inline] > __se_sys_setsockopt net/socket.c:2188 [inline] > __x64_sys_setsockopt+0xba/0x150 net/socket.c:2188 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > Memory state around the buggy address: > ffff88807d37b800: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc > ffff88807d37b880: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc > >ffff88807d37b900: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > ^ > ffff88807d37b980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > ffff88807d37ba00: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc > > Fixes: c85bb41e9318 ("igmp: fix ip_mc_sf_allow race [v5]") > Signed-off-by: Eric Dumazet <edumazet@google.com> > Reported-by: syzbot <syzkaller@googlegroups.com> > Cc: Flavio Leitner <fbl@sysclose.org> > Signed-off-by: David S. Miller <davem@davemloft.net> > --- > This is the backport for 5.10. > It might apply cleanly to older stable trees. It does apply to older trees, thanks for the backport. greg k-h
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index 0c321996c6eb0f20801a81a7ff9d2b134c0453bc..3817988a5a1d44e7b24c94568b75f72d94ad2104 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -2401,9 +2401,10 @@ int ip_mc_source(int add, int omode, struct sock *sk, struct newpsl->sl_addr[i] = psl->sl_addr[i]; /* decrease mem now to avoid the memleak warning */ atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc); - kfree_rcu(psl, rcu); } rcu_assign_pointer(pmc->sflist, newpsl); + if (psl) + kfree_rcu(psl, rcu); psl = newpsl; } rv = 1; /* > 0 for insert logic below if sl_count is 0 */ @@ -2501,11 +2502,13 @@ int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex) psl->sl_count, psl->sl_addr, 0); /* decrease mem now to avoid the memleak warning */ atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc); - kfree_rcu(psl, rcu); - } else + } else { (void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode, 0, NULL, 0); + } rcu_assign_pointer(pmc->sflist, newpsl); + if (psl) + kfree_rcu(psl, rcu); pmc->sfmode = msf->imsf_fmode; err = 0; done: