linux-stable/kernel/bpf
Stanislav Fomichev e9dbb4c539 bpf: prevent decl_tag from being referenced in func_proto
[ Upstream commit ea68376c8b ]

Syzkaller was able to hit the following issue:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 3609 at kernel/bpf/btf.c:1946
btf_type_id_size+0x2d5/0x9d0 kernel/bpf/btf.c:1946
Modules linked in:
CPU: 0 PID: 3609 Comm: syz-executor361 Not tainted
6.0.0-syzkaller-02734-g0326074ff465 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 09/22/2022
RIP: 0010:btf_type_id_size+0x2d5/0x9d0 kernel/bpf/btf.c:1946
Code: ef e8 7f 8e e4 ff 41 83 ff 0b 77 28 f6 44 24 10 18 75 3f e8 6d 91
e4 ff 44 89 fe bf 0e 00 00 00 e8 20 8e e4 ff e8 5b 91 e4 ff <0f> 0b 45
31 f6 e9 98 02 00 00 41 83 ff 12 74 18 e8 46 91 e4 ff 44
RSP: 0018:ffffc90003cefb40 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000000
RDX: ffff8880259c0000 RSI: ffffffff81968415 RDI: 0000000000000005
RBP: ffff88801270ca00 R08: 0000000000000005 R09: 000000000000000e
R10: 0000000000000011 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000011 R14: ffff888026ee6424 R15: 0000000000000011
FS:  000055555641b300(0000) GS:ffff8880b9a00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000f2e258 CR3: 000000007110e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 btf_func_proto_check kernel/bpf/btf.c:4447 [inline]
 btf_check_all_types kernel/bpf/btf.c:4723 [inline]
 btf_parse_type_sec kernel/bpf/btf.c:4752 [inline]
 btf_parse kernel/bpf/btf.c:5026 [inline]
 btf_new_fd+0x1926/0x1e70 kernel/bpf/btf.c:6892
 bpf_btf_load kernel/bpf/syscall.c:4324 [inline]
 __sys_bpf+0xb7d/0x4cf0 kernel/bpf/syscall.c:5010
 __do_sys_bpf kernel/bpf/syscall.c:5069 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5067 [inline]
 __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:5067
 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+0x63/0xcd
RIP: 0033:0x7f0fbae41c69
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc8aeb6228 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0fbae41c69
RDX: 0000000000000020 RSI: 0000000020000140 RDI: 0000000000000012
RBP: 00007f0fbae05e10 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007f0fbae05ea0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Looks like it tries to create a func_proto which return type is
decl_tag. For the details, see Martin's spot on analysis in [0].

0: https://lore.kernel.org/bpf/CAKH8qBuQDLva_hHxxBuZzyAcYNO4ejhovz6TQeVSk8HY-2SO6g@mail.gmail.com/T/#mea6524b3fcd6298347432226e81b1e6155efc62c

Cc: Yonghong Song <yhs@fb.com>
Cc: Martin KaFai Lau <martin.lau@kernel.org>
Fixes: bd16dee66a ("bpf: Add BTF_KIND_DECL_TAG typedef support")
Reported-by: syzbot+d8bd751aef7c6b39a344@syzkaller.appspotmail.com
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221015002444.2680969-2-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-04 00:00:27 +09:00
..
preload bpf: iterators: Build and use lightweight bootstrap version of bpftool 2022-07-15 12:01:30 -07:00
arraymap.c bpf: Acquire map uref in .init_seq_private for array map iterator 2022-08-10 10:12:47 -07:00
bloom_filter.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
bpf_inode_storage.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
bpf_iter.c bpf: Only allow sleepable program for resched-able iterator 2022-08-10 10:12:48 -07:00
bpf_local_storage.c bpf: Use this_cpu_{inc|dec|inc_return} for bpf_task_storage_busy 2022-10-21 12:38:05 +02:00
bpf_lru_list.c bpf_lru_list: Read double-checked variable once without lock 2021-02-10 15:54:26 -08:00
bpf_lru_list.h printk: stop including cache.h from printk.h 2022-05-13 07:20:07 -07:00
bpf_lsm.c bpf: Only add BTF IDs for socket security hooks when CONFIG_SECURITY_NETWORK is on 2022-10-21 12:38:06 +02:00
bpf_struct_ops.c bpf: Remove is_valid_bpf_tramp_flags() 2022-07-11 21:04:58 +02:00
bpf_struct_ops_types.h bpf: Add dummy BPF STRUCT_OPS for test purpose 2021-11-01 14:10:00 -07:00
bpf_task_storage.c bpf: Use this_cpu_{inc|dec|inc_return} for bpf_task_storage_busy 2022-10-21 12:38:05 +02:00
btf.c bpf: prevent decl_tag from being referenced in func_proto 2022-11-04 00:00:27 +09:00
cgroup.c bpf, cgroup: Reject prog_attach_flags array when effective query 2022-10-21 12:38:11 +02:00
core.c bpf: use bpf_prog_pack for bpf_dispatcher 2022-10-21 12:39:11 +02:00
cpumap.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
devmap.c bpf, devmap: Compute proper xdp_frame len redirecting frames 2022-07-26 16:26:19 +02:00
disasm.c bpf: Relicense disassembler as GPL-2.0-only OR BSD-2-Clause 2021-09-02 14:49:23 +02:00
disasm.h bpf: Relicense disassembler as GPL-2.0-only OR BSD-2-Clause 2021-09-02 14:49:23 +02:00
dispatcher.c bpf: use bpf_prog_pack for bpf_dispatcher 2022-10-21 12:39:11 +02:00
hashtab.c bpf: Propagate error from htab_lock_bucket() to userspace 2022-10-21 12:38:05 +02:00
helpers.c btf: Export bpf_dynptr definition 2022-10-21 12:37:37 +02:00
inode.c bpf: Convert bpf_preload.ko to use light skeleton. 2022-02-10 23:31:51 +01:00
Kconfig rcu: Make the TASKS_RCU Kconfig option be selected 2022-04-20 16:52:58 -07:00
link_iter.c bpf: Add bpf_link iterator 2022-05-10 11:20:45 -07:00
local_storage.c bpf: Make non-preallocated allocation low priority 2022-07-12 17:44:27 -07:00
lpm_trie.c bpf: Make non-preallocated allocation low priority 2022-07-12 17:44:27 -07:00
Makefile bpf: Add bpf_link iterator 2022-05-10 11:20:45 -07:00
map_in_map.c bpf: Allow storing unreferenced kptr in map 2022-04-25 17:31:35 -07:00
map_in_map.h
map_iter.c bpf: Introduce MEM_RDONLY flag 2021-12-18 13:27:41 -08:00
mmap_unlock_work.h bpf: Introduce helper bpf_find_vma 2021-11-07 11:54:51 -08:00
net_namespace.c net: Add includes masked by netdevice.h including uapi/bpf.h 2021-12-29 20:03:05 -08:00
offload.c
percpu_freelist.c bpf: avoid grabbing spin_locks of all cpus when no free elems 2022-06-11 14:25:35 -07:00
percpu_freelist.h bpf: Use raw_spin_trylock() for pcpu_freelist_push/pop in NMI 2020-10-06 00:04:11 +02:00
prog_iter.c
queue_stack_maps.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
reuseport_array.c net: Fix suspicious RCU usage in bpf_sk_reuseport_detach() 2022-08-17 16:42:59 -07:00
ringbuf.c bpf: Dynptr support for ring buffers 2022-05-23 14:31:28 -07:00
stackmap.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
syscall.c bpf: Ensure correct locking around vulnerable function find_vpid() 2022-10-21 12:38:11 +02:00
sysfs_btf.c bpf: Load and verify kernel module BTFs 2020-11-10 15:25:53 -08:00
task_iter.c bpf: Remove redundant assignment to meta.seq in __task_seq_show() 2022-04-11 21:14:34 +02:00
tnum.c bpf, tnums: Provably sound, faster, and more precise algorithm for tnum_mul 2021-06-01 13:34:15 +02:00
trampoline.c bpf: Use this_cpu_{inc_return|dec} for prog->active 2022-10-21 12:38:06 +02:00
verifier.c bpf: Fix reference state management for synchronous callbacks 2022-10-21 12:38:03 +02:00