From: Eric Dumazet edumazet@google.com
stable inclusion from stable-5.10.80 commit 9f0e683e1bd4b59c7866c564dd8dce700d7d5365 bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 8ac9dfd58b138f7e82098a4e0a0d46858b12215b ]
Both ifindex and LLC_SK_DEV_HASH_ENTRIES are signed.
This means that (ifindex % LLC_SK_DEV_HASH_ENTRIES) is negative if @ifindex is negative.
We could simply make LLC_SK_DEV_HASH_ENTRIES unsigned.
In this patch I chose to use hash_32() to get more entropy from @ifindex, like llc_sk_laddr_hashfn().
UBSAN: array-index-out-of-bounds in ./include/net/llc.h:75:26 index -43 is out of range for type 'hlist_head [64]' CPU: 1 PID: 20999 Comm: syz-executor.3 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 ubsan_epilogue+0xb/0x5a lib/ubsan.c:151 __ubsan_handle_out_of_bounds.cold+0x62/0x6c lib/ubsan.c:291 llc_sk_dev_hash include/net/llc.h:75 [inline] llc_sap_add_socket+0x49c/0x520 net/llc/llc_conn.c:697 llc_ui_bind+0x680/0xd70 net/llc/af_llc.c:404 __sys_bind+0x1e9/0x250 net/socket.c:1693 __do_sys_bind net/socket.c:1704 [inline] __se_sys_bind net/socket.c:1702 [inline] __x64_sys_bind+0x6f/0xb0 net/socket.c:1702 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+0x44/0xae RIP: 0033:0x7fa503407ae9
Fixes: 6d2e3ea28446 ("llc: use a device based hash table to speed up multicast delivery") Signed-off-by: Eric Dumazet edumazet@google.com Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Chen Jun chenjun102@huawei.com Reviewed-by: Weilong Chen chenweilong@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- include/net/llc.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/net/llc.h b/include/net/llc.h index df282d9b4017..9c10b121b49b 100644 --- a/include/net/llc.h +++ b/include/net/llc.h @@ -72,7 +72,9 @@ struct llc_sap { static inline struct hlist_head *llc_sk_dev_hash(struct llc_sap *sap, int ifindex) { - return &sap->sk_dev_hash[ifindex % LLC_SK_DEV_HASH_ENTRIES]; + u32 bucket = hash_32(ifindex, LLC_SK_DEV_HASH_BITS); + + return &sap->sk_dev_hash[bucket]; }
static inline