From: Eric Dumazet <edumazet@google.com>
Date: Sun, 31 Oct 2021 10:13:53 -0700
Subject: bpf: Add missing map_delete_elem method to bloom filter map
Patch-mainline: v5.16-rc1
Git-commit: ad10c381d133d9f786564bff4b223be1372f6c2a
References: jsc#PED-1377
Without it, kernel crashes in map_delete_elem(), as reported
by syzbot.
BUG: kernel NULL pointer dereference, address: 0000000000000000
PGD 72c97067 P4D 72c97067 PUD 1e20c067 PMD 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 6518 Comm: syz-executor196 Not tainted 5.15.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90002bafcb8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 1ffff92000575f9f RCX: 0000000000000000
RDX: 1ffffffff1327aba RSI: 0000000000000000 RDI: ffff888025a30c00
RBP: ffffc90002baff08 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff818525d8 R11: 0000000000000000 R12: ffffffff8993d560
R13: ffff888025a30c00 R14: ffff888024bc0000 R15: 0000000000000000
FS: 0000555557491300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000070189000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
map_delete_elem kernel/bpf/syscall.c:1220 [inline]
__sys_bpf+0x34f1/0x5ee0 kernel/bpf/syscall.c:4606
__do_sys_bpf kernel/bpf/syscall.c:4719 [inline]
__se_sys_bpf kernel/bpf/syscall.c:4717 [inline]
__x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4717
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
Fixes: 9330986c0300 ("bpf: Add bloom filter map implementation")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211031171353.4092388-1-eric.dumazet@gmail.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
kernel/bpf/bloom_filter.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/kernel/bpf/bloom_filter.c
+++ b/kernel/bpf/bloom_filter.c
@@ -77,6 +77,11 @@ static int bloom_map_pop_elem(struct bpf
return -EOPNOTSUPP;
}
+static int bloom_map_delete_elem(struct bpf_map *map, void *value)
+{
+ return -EOPNOTSUPP;
+}
+
static struct bpf_map *bloom_map_alloc(union bpf_attr *attr)
{
u32 bitset_bytes, bitset_mask, nr_hash_funcs, nr_bits;
@@ -192,6 +197,7 @@ const struct bpf_map_ops bloom_filter_ma
.map_pop_elem = bloom_map_pop_elem,
.map_lookup_elem = bloom_map_lookup_elem,
.map_update_elem = bloom_map_update_elem,
+ .map_delete_elem = bloom_map_delete_elem,
.map_check_btf = bloom_map_check_btf,
.map_btf_name = "bpf_bloom_filter",
.map_btf_id = &bpf_bloom_map_btf_id,