I got multiple syzbot reports showing old bugs exposed by BPF after commit 20f2505fb436 ("bpf: Try to avoid kzalloc in cgroup/{s,g}etsockopt") setsockopt() @optlen argument should be taken into account before copying data. BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset include/linux/sockptr.h:49 [inline] BUG: KASAN: slab-out-of-bounds in copy_from_sockptr include/linux/sockptr.h:55 [inline] BUG: KASAN: slab-out-of-bounds in do_replace net/ipv4/netfilter/ip_tables.c:1111 [inline] BUG: KASAN: slab-out-of-bounds in do_ipt_set_ctl+0x902/0x3dd0 net/ipv4/netfilter/ip_tables.c:1627 Read of size 96 at addr ffff88802cd73da0 by task syz-executor.4/7238 CPU: 1 PID: 7238 Comm: syz-executor.4 Not tainted 6.9.0-rc2-next-20240403-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105 copy_from_sockptr_offset include/linux/sockptr.h:49 [inline] copy_from_sockptr include/linux/sockptr.h:55 [inline] do_replace net/ipv4/netfilter/ip_tables.c:1111 [inline] do_ipt_set_ctl+0x902/0x3dd0 net/ipv4/netfilter/ip_tables.c:1627 nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101 do_sock_setsockopt+0x3af/0x720 net/socket.c:2311 __sys_setsockopt+0x1ae/0x250 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x72/0x7a RIP: 0033:0x7fd22067dde9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd21f9ff0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007fd2207abf80 RCX: 00007fd22067dde9 RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fd2206ca47a R08: 0000000000000001 R09: 0000000000000000 R10: 0000000020000880 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fd2207abf80 R15: 00007ffd2d0170d8 </TASK> Allocated by task 7238: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:4069 [inline] __kmalloc_noprof+0x200/0x410 mm/slub.c:4082 kmalloc_noprof include/linux/slab.h:664 [inline] __cgroup_bpf_run_filter_setsockopt+0xd47/0x1050 kernel/bpf/cgroup.c:1869 do_sock_setsockopt+0x6b4/0x720 net/socket.c:2293 __sys_setsockopt+0x1ae/0x250 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x72/0x7a The buggy address belongs to the object at ffff88802cd73da0 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes inside of allocated 1-byte region [ffff88802cd73da0, ffff88802cd73da1) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802cd73020 pfn:0x2cd73 flags: 0xfff80000000000(node=0|zone=1|lastcpupid=0xfff) page_type: 0xffffefff(slab) raw: 00fff80000000000 ffff888015041280 dead000000000100 dead000000000122 raw: ffff88802cd73020 000000008080007f 00000001ffffefff 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 5103, tgid 2119833701 (syz-executor.4), ts 5103, free_ts 70804600828 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1490 prep_new_page mm/page_alloc.c:1498 [inline] get_page_from_freelist+0x2e7e/0x2f40 mm/page_alloc.c:3454 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4712 __alloc_pages_node_noprof include/linux/gfp.h:244 [inline] alloc_pages_node_noprof include/linux/gfp.h:271 [inline] alloc_slab_page+0x5f/0x120 mm/slub.c:2249 allocate_slab+0x5a/0x2e0 mm/slub.c:2412 new_slab mm/slub.c:2465 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3615 __slab_alloc+0x58/0xa0 mm/slub.c:3705 __slab_alloc_node mm/slub.c:3758 [inline] slab_alloc_node mm/slub.c:3936 [inline] __do_kmalloc_node mm/slub.c:4068 [inline] kmalloc_node_track_caller_noprof+0x286/0x450 mm/slub.c:4089 kstrdup+0x3a/0x80 mm/util.c:62 device_rename+0xb5/0x1b0 drivers/base/core.c:4558 dev_change_name+0x275/0x860 net/core/dev.c:1232 do_setlink+0xa4b/0x41f0 net/core/rtnetlink.c:2864 __rtnl_newlink net/core/rtnetlink.c:3680 [inline] rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3727 rtnetlink_rcv_msg+0x89b/0x10d0 net/core/rtnetlink.c:6594 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2559 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 page last free pid 5146 tgid 5146 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1110 [inline] free_unref_page+0xd3c/0xec0 mm/page_alloc.c:2617 discard_slab mm/slub.c:2511 [inline] __put_partials+0xeb/0x130 mm/slub.c:2980 put_cpu_partial+0x17c/0x250 mm/slub.c:3055 __slab_free+0x2ea/0x3d0 mm/slub.c:4254 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3888 [inline] slab_alloc_node mm/slub.c:3948 [inline] __do_kmalloc_node mm/slub.c:4068 [inline] __kmalloc_node_noprof+0x1d7/0x450 mm/slub.c:4076 kmalloc_node_noprof include/linux/slab.h:681 [inline] kvmalloc_node_noprof+0x72/0x190 mm/util.c:634 bucket_table_alloc lib/rhashtable.c:186 [inline] rhashtable_rehash_alloc+0x9e/0x290 lib/rhashtable.c:367 rht_deferred_worker+0x4e1/0x2440 lib/rhashtable.c:427 process_one_work kernel/workqueue.c:3218 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Memory state around the buggy address: ffff88802cd73c80: 07 fc fc fc 05 fc fc fc 05 fc fc fc fa fc fc fc ffff88802cd73d00: fa fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc >ffff88802cd73d80: fa fc fc fc 01 fc fc fc fa fc fc fc fa fc fc fc ^ ffff88802cd73e00: fa fc fc fc fa fc fc fc 05 fc fc fc 07 fc fc fc ffff88802cd73e80: 07 fc fc fc 07 fc fc fc 07 fc fc fc 07 fc fc fc Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx> Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> --- net/bridge/netfilter/ebtables.c | 6 ++++++ net/ipv4/netfilter/arp_tables.c | 4 ++++ net/ipv4/netfilter/ip_tables.c | 4 ++++ net/ipv6/netfilter/ip6_tables.c | 4 ++++ 4 files changed, 18 insertions(+) diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 99d82676f780ac49d01151fa9c585f44f9ea8ccc..cbd0e3586c3f61904efb4db7d9101d7770c852e7 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -1111,6 +1111,8 @@ static int do_replace(struct net *net, sockptr_t arg, unsigned int len) struct ebt_table_info *newinfo; struct ebt_replace tmp; + if (len < sizeof(tmp)) + return -EINVAL; if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) return -EFAULT; @@ -1423,6 +1425,8 @@ static int update_counters(struct net *net, sockptr_t arg, unsigned int len) { struct ebt_replace hlp; + if (len < sizeof(hlp)) + return -EINVAL; if (copy_from_sockptr(&hlp, arg, sizeof(hlp))) return -EFAULT; @@ -2352,6 +2356,8 @@ static int compat_update_counters(struct net *net, sockptr_t arg, { struct compat_ebt_replace hlp; + if (len < sizeof(hlp)) + return -EINVAL; if (copy_from_sockptr(&hlp, arg, sizeof(hlp))) return -EFAULT; diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 2407066b0fec1121d71561ecbad6f4f87ecdebbc..b150c9929b12e86219a55c77da480e0c538b3449 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -956,6 +956,8 @@ static int do_replace(struct net *net, sockptr_t arg, unsigned int len) void *loc_cpu_entry; struct arpt_entry *iter; + if (len < sizeof(tmp)) + return -EINVAL; if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) return -EFAULT; @@ -1254,6 +1256,8 @@ static int compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) void *loc_cpu_entry; struct arpt_entry *iter; + if (len < sizeof(tmp)) + return -EINVAL; if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) return -EFAULT; diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index 7da1df4997d057a4292927c2041687c2b39d4a01..487670759578168c5ff53bce6642898fc41936b3 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -1108,6 +1108,8 @@ do_replace(struct net *net, sockptr_t arg, unsigned int len) void *loc_cpu_entry; struct ipt_entry *iter; + if (len < sizeof(tmp)) + return -EINVAL; if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) return -EFAULT; @@ -1492,6 +1494,8 @@ compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) void *loc_cpu_entry; struct ipt_entry *iter; + if (len < sizeof(tmp)) + return -EINVAL; if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) return -EFAULT; diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index fd9f049d6d41e77eacc10ce074a8a0d96b0d2e11..636b360311c5365fba2330f6ca2f7f1b6dd1363e 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1125,6 +1125,8 @@ do_replace(struct net *net, sockptr_t arg, unsigned int len) void *loc_cpu_entry; struct ip6t_entry *iter; + if (len < sizeof(tmp)) + return -EINVAL; if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) return -EFAULT; @@ -1501,6 +1503,8 @@ compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) void *loc_cpu_entry; struct ip6t_entry *iter; + if (len < sizeof(tmp)) + return -EINVAL; if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) return -EFAULT; -- 2.44.0.478.gd926399ef9-goog