kernel/net/ipv4/icmp.c, branch linux-6.2.y

icmp: guard against too small mtu

2023-04-13T15:02:38Z

[ Upstream commit 7d63b67125382ff0ffdfca434acbc94a38bd092b ] syzbot was able to trigger a panic [1] in icmp_glue_bits(), or more exactly in skb_copy_and_csum_bits() There is no repro yet, but I think the issue is that syzbot manages to lower device mtu to a small value, fooling __icmp_send() __icmp_send() must make sure there is enough room for the packet to include at least the headers. We might in the future refactor skb_copy_and_csum_bits() and its callers to no longer crash when something bad happens. [1] kernel BUG at net/core/skbuff.c:3343 ! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 15766 Comm: syz-executor.0 Not tainted 6.3.0-rc4-syzkaller-00039-gffe78bbd5121 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 RIP: 0010:skb_copy_and_csum_bits+0x798/0x860 net/core/skbuff.c:3343 Code: f0 c1 c8 08 41 89 c6 e9 73 ff ff ff e8 61 48 d4 f9 e9 41 fd ff ff 48 8b 7c 24 48 e8 52 48 d4 f9 e9 c3 fc ff ff e8 c8 27 84 f9 <0f> 0b 48 89 44 24 28 e8 3c 48 d4 f9 48 8b 44 24 28 e9 9d fb ff ff RSP: 0018:ffffc90000007620 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00000000000001e8 RCX: 0000000000000100 RDX: ffff8880276f6280 RSI: ffffffff87fdd138 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 00000000000001e8 R11: 0000000000000001 R12: 000000000000003c R13: 0000000000000000 R14: ffff888028244868 R15: 0000000000000b0e FS: 00007fbc81f1c700(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2df43000 CR3: 00000000744db000 CR4: 0000000000150ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: icmp_glue_bits+0x7b/0x210 net/ipv4/icmp.c:353 __ip_append_data+0x1d1b/0x39f0 net/ipv4/ip_output.c:1161 ip_append_data net/ipv4/ip_output.c:1343 [inline] ip_append_data+0x115/0x1a0 net/ipv4/ip_output.c:1322 icmp_push_reply+0xa8/0x440 net/ipv4/icmp.c:370 __icmp_send+0xb80/0x1430 net/ipv4/icmp.c:765 ipv4_send_dest_unreach net/ipv4/route.c:1239 [inline] ipv4_link_failure+0x5a9/0x9e0 net/ipv4/route.c:1246 dst_link_failure include/net/dst.h:423 [inline] arp_error_report+0xcb/0x1c0 net/ipv4/arp.c:296 neigh_invalidate+0x20d/0x560 net/core/neighbour.c:1079 neigh_timer_handler+0xc77/0xff0 net/core/neighbour.c:1166 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700 expire_timers+0x29b/0x4b0 kernel/time/timer.c:1751 __run_timers kernel/time/timer.c:2022 [inline] Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+d373d60fddbdc915e666@syzkaller.appspotmail.com Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20230330174502.1915328-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

treewide: use get_random_u32_below() instead of deprecated function

2022-11-18T01:15:15Z

This is a simple mechanical transformation done by: @@ expression E; @@ - prandom_u32_max + get_random_u32_below (E) Reviewed-by: Kees Cook Reviewed-by: Greg Kroah-Hartman Acked-by: Darrick J. Wong # for xfs Reviewed-by: SeongJae Park # for damon Reviewed-by: Jason Gunthorpe # for infiniband Reviewed-by: Russell King (Oracle) # for arm Acked-by: Ulf Hansson # for mmc Signed-off-by: Jason A. Donenfeld

ip: Fix data-races around sysctl_ip_no_pmtu_disc.

2022-07-15T10:49:55Z

While reading sysctl_ip_no_pmtu_disc, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

icmp: Fix a data-race around sysctl_icmp_ratemask.

2022-07-13T11:56:49Z

While reading sysctl_icmp_ratemask, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

icmp: Fix a data-race around sysctl_icmp_ratelimit.

2022-07-13T11:56:49Z

While reading sysctl_icmp_ratelimit, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

icmp: Fix a data-race around sysctl_icmp_errors_use_inbound_ifaddr.

2022-07-13T11:56:49Z

While reading sysctl_icmp_errors_use_inbound_ifaddr, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1c2fb7f93cb2 ("[IPV4]: Sysctl configurable icmp error source address.") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

icmp: Fix a data-race around sysctl_icmp_ignore_bogus_error_responses.

2022-07-13T11:56:49Z

While reading sysctl_icmp_ignore_bogus_error_responses, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

icmp: Fix a data-race around sysctl_icmp_echo_ignore_broadcasts.

2022-07-13T11:56:49Z

While reading sysctl_icmp_echo_ignore_broadcasts, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

icmp: Fix data-races around sysctl_icmp_echo_enable_probe.

2022-07-13T11:56:49Z

While reading sysctl_icmp_echo_enable_probe, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: d329ea5bd884 ("icmp: add response to RFC 8335 PROBE messages") Fixes: 1fd07f33c3ea ("ipv6: ICMPV6: add response to ICMPV6 RFC 8335 PROBE messages") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

icmp: Fix a data-race around sysctl_icmp_echo_ignore_all.

2022-07-13T11:56:49Z

While reading sysctl_icmp_echo_ignore_all, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller