Eric Dumazet 0c722a32f2 bpf: Make sure mac_header was set before using it ... commit 0326195f523a549e0a9d7fd44c70b26fd7265090 upstream. Classic BPF has a way to load bytes starting from the mac header. Some skbs do not have a mac header, and skb_mac_header() in this case is returning a pointer that 65535 bytes after skb->head. Existing range check in bpf_internal_load_pointer_neg_helper() was properly kicking and no illegal access was happening. New sanity check in skb_mac_header() is firing, so we need to avoid it. WARNING: CPU: 1 PID: 28990 at include/linux/skbuff.h:2785 skb_mac_header include/linux/skbuff.h:2785 [inline] WARNING: CPU: 1 PID: 28990 at include/linux/skbuff.h:2785 bpf_internal_load_pointer_neg_helper+0x1b1/0x1c0 kernel/bpf/core.c:74 Modules linked in: CPU: 1 PID: 28990 Comm: syz-executor.0 Not tainted 5.19.0-rc4-syzkaller-00865-g4874fb9484be #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 RIP: 0010:skb_mac_header include/linux/skbuff.h:2785 [inline] RIP: 0010:bpf_internal_load_pointer_neg_helper+0x1b1/0x1c0 kernel/bpf/core.c:74 Code: ff ff 45 31 f6 e9 5a ff ff ff e8 aa 27 40 00 e9 3b ff ff ff e8 90 27 40 00 e9 df fe ff ff e8 86 27 40 00 eb 9e e8 2f 2c f3 ff <0f> 0b eb b1 e8 96 27 40 00 e9 79 fe ff ff 90 41 57 41 56 41 55 41 RSP: 0018:ffffc9000309f668 EFLAGS: 00010216 RAX: 0000000000000118 RBX: ffffffffffeff00c RCX: ffffc9000e417000 RDX: 0000000000040000 RSI: ffffffff81873f21 RDI: 0000000000000003 RBP: ffff8880842878c0 R08: 0000000000000003 R09: 000000000000ffff R10: 000000000000ffff R11: 0000000000000001 R12: 0000000000000004 R13: ffff88803ac56c00 R14: 000000000000ffff R15: dffffc0000000000 FS: 00007f5c88a16700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdaa9f6c058 CR3: 000000003a82c000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ____bpf_skb_load_helper_32 net/core/filter.c:276 [inline] bpf_skb_load_helper_32+0x191/0x220 net/core/filter.c:264 Fixes: f9aefd6b2aa3 ("net: warn if mac header was not set") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220707123900.945305-1-edumazet@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-07-29 17:19:23 +02:00
..
preload	bpf: Fix umd memory leak in copy_process()	2021-03-30 14:32:03 +02:00
arraymap.c	bpf: Fix potential race in tail call compatibility check	2021-11-02 19:48:21 +01:00
bpf_inode_storage.c	bpf: Change inode_storage's lookup_elem return value from NULL to -EBADF	2021-03-30 14:31:56 +02:00
bpf_iter.c
bpf_local_storage.c
bpf_lru_list.c
bpf_lru_list.h
bpf_lsm.c
bpf_struct_ops_types.h
bpf_struct_ops.c	bpf: Handle return value of BPF_PROG_TYPE_STRUCT_OPS prog	2021-10-06 15:55:50 +02:00
btf.c	bpf: Disallow BPF_LOG_KERNEL log level for bpf(BPF_BTF_LOAD)	2022-01-27 10:53:54 +01:00
cgroup.c
core.c	bpf: Make sure mac_header was set before using it	2022-07-29 17:19:23 +02:00
cpumap.c
devmap.c	bpf: Fix integer overflow in argument calculation for bpf_map_area_alloc	2021-12-17 10:14:41 +01:00
disasm.c	bpf: Introduce BPF nospec instruction for mitigating Spectre v4	2021-08-04 12:46:44 +02:00
disasm.h
dispatcher.c
hashtab.c	bpf: Fix integer overflow involving bucket_size	2021-08-18 08:59:10 +02:00
helpers.c	bpf: Fix potentially incorrect results with bpf_get_local_storage()	2021-09-03 10:09:31 +02:00
inode.c	bpf: link: Refuse non-O_RDWR flags in BPF_OBJ_GET	2021-04-14 08:42:00 +02:00
local_storage.c	bpf: Fix NULL pointer dereference in bpf_get_local_storage() helper	2021-09-03 10:09:21 +02:00
lpm_trie.c
Makefile
map_in_map.c
map_in_map.h
map_iter.c
net_namespace.c
offload.c
percpu_freelist.c
percpu_freelist.h
prog_iter.c
queue_stack_maps.c
reuseport_array.c
ringbuf.c	bpf: Use VM_MAP instead of VM_ALLOC for ringbuf	2022-02-08 18:30:39 +01:00
stackmap.c	bpf: Fix incorrect memory charge cost calculation in stack_map_alloc()	2022-06-22 14:13:12 +02:00
syscall.c	bpf: Add schedule points in batch ops	2022-03-02 11:42:49 +01:00
sysfs_btf.c
task_iter.c
tnum.c
trampoline.c	bpf: Fix potential array overflow in bpf_trampoline_get_progs()	2022-06-06 08:42:45 +02:00
verifier.c	bpf: Fix insufficient bounds propagation from adjust_scalar_min_max_vals	2022-07-12 16:32:17 +02:00