Craig Gallek 8c01c4f896 bpf: fix verifier NULL pointer dereference ... do_check() can fail early without allocating env->cur_state under memory pressure. Syzkaller found the stack below on the linux-next tree because of this. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 27062 Comm: syz-executor5 Not tainted 4.14.0-rc7+ #106 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801c2c74700 task.stack: ffff8801c3e28000 RIP: 0010:free_verifier_state kernel/bpf/verifier.c:347 [inline] RIP: 0010:bpf_check+0xcf4/0x19c0 kernel/bpf/verifier.c:4533 RSP: 0018:ffff8801c3e2f5c8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 00000000fffffff4 RCX: 0000000000000000 RDX: 0000000000000070 RSI: ffffffff817d5aa9 RDI: 0000000000000380 RBP: ffff8801c3e2f668 R08: 0000000000000000 R09: 1ffff100387c5d9f R10: 00000000218c4e80 R11: ffffffff85b34380 R12: ffff8801c4dc6a28 R13: 0000000000000000 R14: ffff8801c4dc6a00 R15: ffff8801c4dc6a20 FS: 00007f311079b700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004d4a24 CR3: 00000001cbcd0000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bpf_prog_load+0xcbb/0x18e0 kernel/bpf/syscall.c:1166 SYSC_bpf kernel/bpf/syscall.c:1690 [inline] SyS_bpf+0xae9/0x4620 kernel/bpf/syscall.c:1652 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x452869 RSP: 002b:00007f311079abe8 EFLAGS: 00000212 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452869 RDX: 0000000000000030 RSI: 0000000020168000 RDI: 0000000000000005 RBP: 00007f311079aa20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004b7550 R13: 00007f311079ab58 R14: 00000000004b7560 R15: 0000000000000000 Code: df 48 c1 ea 03 80 3c 02 00 0f 85 e6 0b 00 00 4d 8b 6e 20 48 b8 00 00 00 00 00 fc ff df 49 8d bd 80 03 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 b6 0b 00 00 49 8b bd 80 03 00 00 e8 d6 0c 26 RIP: free_verifier_state kernel/bpf/verifier.c:347 [inline] RSP: ffff8801c3e2f5c8 RIP: bpf_check+0xcf4/0x19c0 kernel/bpf/verifier.c:4533 RSP: ffff8801c3e2f5c8 ---[ end trace c8d37f339dc64004 ]--- Fixes: 638f5b90d4 ("bpf: reduce verifier memory consumption") Fixes: 1969db47f8 ("bpf: fix verifier memory leaks") Signed-off-by: Craig Gallek <kraig@google.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>		2017-11-03 15:49:15 +09:00
..
arraymap.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2017-10-22 13:39:14 +01:00
bpf_lru_list.c	bpf: lru: Lower the PERCPU_NR_SCANS from 16 to 4	2017-04-17 13:55:52 -04:00
bpf_lru_list.h	bpf: Only set node->ref = 1 if it has not been set	2017-09-01 09:57:39 -07:00
cgroup.c	bpf: remove redundant variable old_flags	2017-10-11 20:22:34 -07:00
core.c	bpf: permit multiple bpf attachments for a single perf event	2017-10-25 10:47:47 +09:00
cpumap.c	bpf: cpumap micro-optimization in cpu_map_enqueue	2017-11-02 16:13:14 +09:00
devmap.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2017-10-22 13:39:14 +01:00
disasm.c	bpf: move instruction printing into a separate file	2017-10-10 12:30:16 -07:00
disasm.h	bpf: move instruction printing into a separate file	2017-10-10 12:30:16 -07:00
hashtab.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2017-10-22 13:39:14 +01:00
helpers.c	bpf: rename ARG_PTR_TO_STACK	2017-01-09 16:56:27 -05:00
inode.c	bpf: Add file mode configuration into bpf maps	2017-10-20 13:32:59 +01:00
lpm_trie.c	bpf: Add file mode configuration into bpf maps	2017-10-20 13:32:59 +01:00
Makefile	bpf: introduce new bpf cpu map type BPF_MAP_TYPE_CPUMAP	2017-10-18 12:12:18 +01:00
map_in_map.c	bpf: Add syscall lookup support for fd array and htab	2017-06-29 13:13:25 -04:00
map_in_map.h	bpf: Add syscall lookup support for fd array and htab	2017-06-29 13:13:25 -04:00
percpu_freelist.c	bpf: introduce percpu_freelist	2016-03-08 15:28:31 -05:00
percpu_freelist.h	bpf: introduce percpu_freelist	2016-03-08 15:28:31 -05:00
sockmap.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2017-11-02 15:23:39 +09:00
stackmap.c	bpf: Add file mode configuration into bpf maps	2017-10-20 13:32:59 +01:00
syscall.c	selinux: bpf: Add addtional check for bpf object file receive	2017-10-20 13:32:59 +01:00
tnum.c	bpf/verifier: track signed and unsigned min/max values	2017-08-08 17:51:34 -07:00
verifier.c	bpf: fix verifier NULL pointer dereference	2017-11-03 15:49:15 +09:00