Revision 49054556289e8787501630b7c7a9d407da02e296 authored by Paolo Abeni on 29 September 2021, 09:59:17 UTC, committed by David S. Miller on 30 September 2021, 12:06:47 UTC
Syzkaller reported a false positive deadlock involving the nl socket lock and the subflow socket lock: MPTCP: kernel_bind error, err=-98 ============================================ WARNING: possible recursive locking detected 5.15.0-rc1-syzkaller #0 Not tainted -------------------------------------------- syz-executor998/6520 is trying to acquire lock: ffff8880795718a0 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x267/0x7b0 net/mptcp/protocol.c:2738 but task is already holding lock: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline] ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x23/0x7b0 net/mptcp/protocol.c:2720 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(k-sk_lock-AF_INET); lock(k-sk_lock-AF_INET); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by syz-executor998/6520: #0: ffffffff8d176c50 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802 #1: ffffffff8d176d08 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8d176d08 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x3e0/0x580 net/netlink/genetlink.c:790 #2: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline] #2: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x23/0x7b0 net/mptcp/protocol.c:2720 stack backtrace: CPU: 1 PID: 6520 Comm: syz-executor998 Not tainted 5.15.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2944 [inline] check_deadlock kernel/locking/lockdep.c:2987 [inline] validate_chain kernel/locking/lockdep.c:3776 [inline] __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 lock_sock_fast+0x36/0x100 net/core/sock.c:3229 mptcp_close+0x267/0x7b0 net/mptcp/protocol.c:2738 inet_release+0x12e/0x280 net/ipv4/af_inet.c:431 __sock_release net/socket.c:649 [inline] sock_release+0x87/0x1b0 net/socket.c:677 mptcp_pm_nl_create_listen_socket+0x238/0x2c0 net/mptcp/pm_netlink.c:900 mptcp_nl_cmd_add_addr+0x359/0x930 net/mptcp/pm_netlink.c:1170 genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:731 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 sock_no_sendpage+0x101/0x150 net/core/sock.c:2980 kernel_sendpage.part.0+0x1a0/0x340 net/socket.c:3504 kernel_sendpage net/socket.c:3501 [inline] sock_sendpage+0xe5/0x140 net/socket.c:1003 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x43e/0x8a0 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:746 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0xae9/0x1240 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1314 [inline] __se_sys_sendfile64 fs/read_write.c:1300 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1300 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: 0033:0x7f215cb69969 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 00 00 90 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:00007ffc96bb3868 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f215cbad072 RCX: 00007f215cb69969 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005 RBP: 0000000000000000 R08: 00007ffc96bb3a08 R09: 00007ffc96bb3a08 R10: 0000000100000002 R11: 0000000000000246 R12: 00007ffc96bb387c R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000 the problem originates from uncorrect lock annotation in the mptcp code and is only visible since commit 2dcb96bacce3 ("net: core: Correct the sock::sk_lock.owned lockdep annotations"), but is present since the port-based endpoint support initial implementation. This patch addresses the issue introducing a nested variant of lock_sock_fast() and using it in the relevant code path. Fixes: 1729cf186d8a ("mptcp: create the listening socket for new port") Fixes: 2dcb96bacce3 ("net: core: Correct the sock::sk_lock.owned lockdep annotations") Suggested-by: Thomas Gleixner <tglx@linutronix.de> Reported-and-tested-by: syzbot+1dd53f7a89b299d59eaf@syzkaller.appspotmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent d88fd1b
s390vx.uc
// SPDX-License-Identifier: GPL-2.0
/*
* raid6_vx$#.c
*
* $#-way unrolled RAID6 gen/xor functions for s390
* based on the vector facility
*
* Copyright IBM Corp. 2016
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
*
* This file is postprocessed using unroll.awk.
*/
#include <linux/raid/pq.h>
#include <asm/fpu/api.h>
asm(".include \"asm/vx-insn.h\"\n");
#define NSIZE 16
static inline void LOAD_CONST(void)
{
asm volatile("VREPIB %v24,7");
asm volatile("VREPIB %v25,0x1d");
}
/*
* The SHLBYTE() operation shifts each of the 16 bytes in
* vector register y left by 1 bit and stores the result in
* vector register x.
*/
static inline void SHLBYTE(int x, int y)
{
asm volatile ("VAB %0,%1,%1" : : "i" (x), "i" (y));
}
/*
* For each of the 16 bytes in the vector register y the MASK()
* operation returns 0xFF if the high bit of the byte is 1,
* or 0x00 if the high bit is 0. The result is stored in vector
* register x.
*/
static inline void MASK(int x, int y)
{
asm volatile ("VESRAVB %0,%1,24" : : "i" (x), "i" (y));
}
static inline void AND(int x, int y, int z)
{
asm volatile ("VN %0,%1,%2" : : "i" (x), "i" (y), "i" (z));
}
static inline void XOR(int x, int y, int z)
{
asm volatile ("VX %0,%1,%2" : : "i" (x), "i" (y), "i" (z));
}
static inline void LOAD_DATA(int x, u8 *ptr)
{
typedef struct { u8 _[16 * $#]; } addrtype;
register addrtype *__ptr asm("1") = (addrtype *) ptr;
asm volatile ("VLM %2,%3,0,%1"
: : "m" (*__ptr), "a" (__ptr), "i" (x),
"i" (x + $# - 1));
}
static inline void STORE_DATA(int x, u8 *ptr)
{
typedef struct { u8 _[16 * $#]; } addrtype;
register addrtype *__ptr asm("1") = (addrtype *) ptr;
asm volatile ("VSTM %2,%3,0,1"
: "=m" (*__ptr) : "a" (__ptr), "i" (x),
"i" (x + $# - 1));
}
static inline void COPY_VEC(int x, int y)
{
asm volatile ("VLR %0,%1" : : "i" (x), "i" (y));
}
static void raid6_s390vx$#_gen_syndrome(int disks, size_t bytes, void **ptrs)
{
struct kernel_fpu vxstate;
u8 **dptr, *p, *q;
int d, z, z0;
kernel_fpu_begin(&vxstate, KERNEL_VXR);
LOAD_CONST();
dptr = (u8 **) ptrs;
z0 = disks - 3; /* Highest data disk */
p = dptr[z0 + 1]; /* XOR parity */
q = dptr[z0 + 2]; /* RS syndrome */
for (d = 0; d < bytes; d += $#*NSIZE) {
LOAD_DATA(0,&dptr[z0][d]);
COPY_VEC(8+$$,0+$$);
for (z = z0 - 1; z >= 0; z--) {
MASK(16+$$,8+$$);
AND(16+$$,16+$$,25);
SHLBYTE(8+$$,8+$$);
XOR(8+$$,8+$$,16+$$);
LOAD_DATA(16,&dptr[z][d]);
XOR(0+$$,0+$$,16+$$);
XOR(8+$$,8+$$,16+$$);
}
STORE_DATA(0,&p[d]);
STORE_DATA(8,&q[d]);
}
kernel_fpu_end(&vxstate, KERNEL_VXR);
}
static void raid6_s390vx$#_xor_syndrome(int disks, int start, int stop,
size_t bytes, void **ptrs)
{
struct kernel_fpu vxstate;
u8 **dptr, *p, *q;
int d, z, z0;
dptr = (u8 **) ptrs;
z0 = stop; /* P/Q right side optimization */
p = dptr[disks - 2]; /* XOR parity */
q = dptr[disks - 1]; /* RS syndrome */
kernel_fpu_begin(&vxstate, KERNEL_VXR);
LOAD_CONST();
for (d = 0; d < bytes; d += $#*NSIZE) {
/* P/Q data pages */
LOAD_DATA(0,&dptr[z0][d]);
COPY_VEC(8+$$,0+$$);
for (z = z0 - 1; z >= start; z--) {
MASK(16+$$,8+$$);
AND(16+$$,16+$$,25);
SHLBYTE(8+$$,8+$$);
XOR(8+$$,8+$$,16+$$);
LOAD_DATA(16,&dptr[z][d]);
XOR(0+$$,0+$$,16+$$);
XOR(8+$$,8+$$,16+$$);
}
/* P/Q left side optimization */
for (z = start - 1; z >= 0; z--) {
MASK(16+$$,8+$$);
AND(16+$$,16+$$,25);
SHLBYTE(8+$$,8+$$);
XOR(8+$$,8+$$,16+$$);
}
LOAD_DATA(16,&p[d]);
XOR(16+$$,16+$$,0+$$);
STORE_DATA(16,&p[d]);
LOAD_DATA(16,&q[d]);
XOR(16+$$,16+$$,8+$$);
STORE_DATA(16,&q[d]);
}
kernel_fpu_end(&vxstate, KERNEL_VXR);
}
static int raid6_s390vx$#_valid(void)
{
return MACHINE_HAS_VX;
}
const struct raid6_calls raid6_s390vx$# = {
raid6_s390vx$#_gen_syndrome,
raid6_s390vx$#_xor_syndrome,
raid6_s390vx$#_valid,
"vx128x$#",
1
};
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