[ Upstream commit a35c04de2565db191726b5741e6b66a35002c652 ]
smc_lo_register_dmb() allocates DMB buffers with kzalloc(), which are
later passed to get_page() in smc_rx_splice(). Since kmalloc memory is
not page-backed, this triggers WARN_ON_ONCE() in get_page() and prevents
holding a refcount on the buffer. This can lead to use-after-free if
the memory is released before splice_to_pipe() completes.
Use folio_alloc() instead, ensuring DMBs are page-backed and safe for
get_page().
WARNING: CPU: 18 PID: 12152 at ./include/linux/mm.h:1330 smc_rx_splice+0xaf8/0xe20 [smc]
CPU: 18 UID: 0 PID: 12152 Comm: smcapp Kdump: loaded Not tainted 6.17.0-rc3-11705-g9cf4672ecfee #10 NONE
Hardware name: IBM 3931 A01 704 (z/VM 7.4.0)
Krnl PSW : 0704e00180000000 000793161032696c (smc_rx_splice+0xafc/0xe20 [smc])
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000000 001cee80007d3001 00077400000000f8 0000000000000005
0000000000000001 001cee80007d3006 0007740000001000 001c000000000000
000000009b0c99e0 0000000000001000 001c0000000000f8 001c000000000000
000003ffcc6f7c88 0007740003e98000 0007931600000005 000792969b2ff7b8
Krnl Code: 0007931610326960: af000000 mc 0,0
0007931610326964: a7f4ff43 brc 15,00079316103267ea
#0007931610326968: af000000 mc 0,0
>000793161032696c: a7f4ff3f brc 15,00079316103267ea
0007931610326970: e320f1000004 lg %r2,256(%r15)
0007931610326976: c0e53fd1b5f5 brasl %r14,000793168fd5d560
000793161032697c: a7f4fbb5 brc 15,00079316103260e6
0007931610326980: b904002b lgr %r2,%r11
Call Trace:
smc_rx_splice+0xafc/0xe20 [smc]
smc_rx_splice+0x756/0xe20 [smc])
smc_rx_recvmsg+0xa74/0xe00 [smc]
smc_splice_read+0x1ce/0x3b0 [smc]
sock_splice_read+0xa2/0xf0
do_splice_read+0x198/0x240
splice_file_to_pipe+0x7e/0x110
do_splice+0x59e/0xde0
__do_splice+0x11a/0x2d0
__s390x_sys_splice+0x140/0x1f0
__do_syscall+0x122/0x280
system_call+0x6e/0x90
Last Breaking-Event-Address:
smc_rx_splice+0x960/0xe20 [smc]
---[ end trace 0000000000000000 ]---
Fixes: f7a22071dbf3 ("net/smc: implement DMB-related operations of loopback-ism")
Reviewed-by: Mahanta Jambigi <mjambigi@linux.ibm.com>
Signed-off-by: Sidraya Jayagond <sidraya@linux.ibm.com>
Link: https://patch.msgid.link/20250917184220.801066-1-sidraya@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cc282f73bc0cbdf3ee7af2f2d3a2ef4e6b19242d ]
Currently SMC code is validating the reserved bits while parsing the incoming
CLC decline message & when this validation fails, its treated as a protocol
error. As a result, the SMC connection is terminated instead of falling back to
TCP. As per RFC7609[1] specs we shouldn't be validating the reserved bits that
is part of CLC message. This patch fixes this issue.
CLC Decline message format can viewed here[2].
[1] https://datatracker.ietf.org/doc/html/rfc7609#page-92
[2] https://datatracker.ietf.org/doc/html/rfc7609#page-105
Fixes: 8ade200c269f ("net/smc: add v2 format of CLC decline message")
Signed-off-by: Mahanta Jambigi <mjambigi@linux.ibm.com>
Reviewed-by: Sidraya Jayagond <sidraya@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Link: https://patch.msgid.link/20250902082041.98996-1-mjambigi@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c51da3f7a161c6822232be832abdffe47eb55b4c ]
Difference between sock_i_uid() and sk_uid() is that
after sock_orphan(), sock_i_uid() returns GLOBAL_ROOT_UID
while sk_uid() returns the last cached sk->sk_uid value.
None of sock_i_uid() callers care about this.
Use sk_uid() which is much faster and inlined.
Note that diag/dump users are calling sock_i_ino() and
can not see the full benefit yet.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://patch.msgid.link/20250620133001.4090592-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 5d6b58c932ec ("net: lockless sock_i_ino()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ba1e9421cf1a8369d25c3832439702a015d6b5f9 ]
BUG: kernel NULL pointer dereference, address: 00000000000002ec
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP PTI
CPU: 28 UID: 0 PID: 343 Comm: kworker/28:1 Kdump: loaded Tainted: G OE 6.17.0-rc2+ #9 NONE
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
Workqueue: smc_hs_wq smc_listen_work [smc]
RIP: 0010:smc_ib_is_sg_need_sync+0x9e/0xd0 [smc]
...
Call Trace:
<TASK>
smcr_buf_map_link+0x211/0x2a0 [smc]
__smc_buf_create+0x522/0x970 [smc]
smc_buf_create+0x3a/0x110 [smc]
smc_find_rdma_v2_device_serv+0x18f/0x240 [smc]
? smc_vlan_by_tcpsk+0x7e/0xe0 [smc]
smc_listen_find_device+0x1dd/0x2b0 [smc]
smc_listen_work+0x30f/0x580 [smc]
process_one_work+0x18c/0x340
worker_thread+0x242/0x360
kthread+0xe7/0x220
ret_from_fork+0x13a/0x160
ret_from_fork_asm+0x1a/0x30
</TASK>
If the software RoCE device is used, ibdev->dma_device is a null pointer.
As a result, the problem occurs. Null pointer detection is added to
prevent problems.
Fixes: 0ef69e788411c ("net/smc: optimize for smc_sndbuf_sync_sg_for_device and smc_rmb_sync_sg_for_cpu")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Reviewed-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
Link: https://patch.msgid.link/20250828124117.2622624-1-liujian56@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d9cef55ed49117bd63695446fb84b4b91815c0b4 ]
BPF CI testing report a UAF issue:
[ 16.446633] BUG: kernel NULL pointer dereference, address: 000000000000003 0
[ 16.447134] #PF: supervisor read access in kernel mod e
[ 16.447516] #PF: error_code(0x0000) - not-present pag e
[ 16.447878] PGD 0 P4D 0
[ 16.448063] Oops: Oops: 0000 [#1] PREEMPT SMP NOPT I
[ 16.448409] CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Tainted: G OE 6.13.0-rc3-g89e8a75fda73-dirty #4 2
[ 16.449124] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODUL E
[ 16.449502] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/201 4
[ 16.450201] Workqueue: smc_hs_wq smc_listen_wor k
[ 16.450531] RIP: 0010:smc_listen_work+0xc02/0x159 0
[ 16.452158] RSP: 0018:ffffb5ab40053d98 EFLAGS: 0001024 6
[ 16.452526] RAX: 0000000000000001 RBX: 0000000000000002 RCX: 000000000000030 0
[ 16.452994] RDX: 0000000000000280 RSI: 00003513840053f0 RDI: 000000000000000 0
[ 16.453492] RBP: ffffa097808e3800 R08: ffffa09782dba1e0 R09: 000000000000000 5
[ 16.453987] R10: 0000000000000000 R11: 0000000000000000 R12: ffffa0978274640 0
[ 16.454497] R13: 0000000000000000 R14: 0000000000000000 R15: ffffa09782d4092 0
[ 16.454996] FS: 0000000000000000(0000) GS:ffffa097bbc00000(0000) knlGS:000000000000000 0
[ 16.455557] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003 3
[ 16.455961] CR2: 0000000000000030 CR3: 0000000102788004 CR4: 0000000000770ef 0
[ 16.456459] PKRU: 5555555 4
[ 16.456654] Call Trace :
[ 16.456832] <TASK >
[ 16.456989] ? __die+0x23/0x7 0
[ 16.457215] ? page_fault_oops+0x180/0x4c 0
[ 16.457508] ? __lock_acquire+0x3e6/0x249 0
[ 16.457801] ? exc_page_fault+0x68/0x20 0
[ 16.458080] ? asm_exc_page_fault+0x26/0x3 0
[ 16.458389] ? smc_listen_work+0xc02/0x159 0
[ 16.458689] ? smc_listen_work+0xc02/0x159 0
[ 16.458987] ? lock_is_held_type+0x8f/0x10 0
[ 16.459284] process_one_work+0x1ea/0x6d 0
[ 16.459570] worker_thread+0x1c3/0x38 0
[ 16.459839] ? __pfx_worker_thread+0x10/0x1 0
[ 16.460144] kthread+0xe0/0x11 0
[ 16.460372] ? __pfx_kthread+0x10/0x1 0
[ 16.460640] ret_from_fork+0x31/0x5 0
[ 16.460896] ? __pfx_kthread+0x10/0x1 0
[ 16.461166] ret_from_fork_asm+0x1a/0x3 0
[ 16.461453] </TASK >
[ 16.461616] Modules linked in: bpf_testmod(OE) [last unloaded: bpf_testmod(OE) ]
[ 16.462134] CR2: 000000000000003 0
[ 16.462380] ---[ end trace 0000000000000000 ]---
[ 16.462710] RIP: 0010:smc_listen_work+0xc02/0x1590
The direct cause of this issue is that after smc_listen_out_connected(),
newclcsock->sk may be NULL since it will releases the smcsk. Therefore,
if the application closes the socket immediately after accept,
newclcsock->sk can be NULL. A possible execution order could be as
follows:
smc_listen_work | userspace
-----------------------------------------------------------------
lock_sock(sk) |
smc_listen_out_connected() |
| \- smc_listen_out |
| | \- release_sock |
| |- sk->sk_data_ready() |
| fd = accept();
| close(fd);
| \- socket->sk = NULL;
/* newclcsock->sk is NULL now */
SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk))
Since smc_listen_out_connected() will not fail, simply swapping the order
of the code can easily fix this issue.
Fixes: 3b2dec2603d5 ("net/smc: restructure client and server code in af_smc")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Link: https://patch.msgid.link/20250818054618.41615-1-alibuda@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
syzbot reported weird splats [0][1] in cipso_v4_sock_setattr() while
freeing inet_sk(sk)->inet_opt.
The address was freed multiple times even though it was read-only memory.
cipso_v4_sock_setattr() did nothing wrong, and the root cause was type
confusion.
The cited commit made it possible to create smc_sock as an INET socket.
The issue is that struct smc_sock does not have struct inet_sock as the
first member but hijacks AF_INET and AF_INET6 sk_family, which confuses
various places.
In this case, inet_sock.inet_opt was actually smc_sock.clcsk_data_ready(),
which is an address of a function in the text segment.
$ pahole -C inet_sock vmlinux
struct inet_sock {
...
struct ip_options_rcu * inet_opt; /* 784 8 */
$ pahole -C smc_sock vmlinux
struct smc_sock {
...
void (*clcsk_data_ready)(struct sock *); /* 784 8 */
The same issue for another field was reported before. [2][3]
At that time, an ugly hack was suggested [4], but it makes both INET
and SMC code error-prone and hard to change.
Also, yet another variant was fixed by a hacky commit 98d4435efcbf3
("net/smc: prevent NULL pointer dereference in txopt_get").
Instead of papering over the root cause by such hacks, we should not
allow non-INET socket to reuse the INET infra.
Let's add inet_sock as the first member of smc_sock.
[0]:
kvfree_call_rcu(): Double-freed call. rcu_head 000000006921da73
WARNING: CPU: 0 PID: 6718 at mm/slab_common.c:1956 kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955
Modules linked in:
CPU: 0 UID: 0 PID: 6718 Comm: syz.0.17 Tainted: G W 6.16.0-rc4-syzkaller-g7482bb149b9f #0 PREEMPT
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955
lr : kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955
sp : ffff8000a03a7730
x29: ffff8000a03a7730 x28: 00000000fffffff5 x27: 1fffe000184823d3
x26: dfff800000000000 x25: ffff0000c2411e9e x24: ffff0000dd88da00
x23: ffff8000891ac9a0 x22: 00000000ffffffea x21: ffff8000891ac9a0
x20: ffff8000891ac9a0 x19: ffff80008afc2480 x18: 00000000ffffffff
x17: 0000000000000000 x16: ffff80008ae642c8 x15: ffff700011ede14c
x14: 1ffff00011ede14c x13: 0000000000000004 x12: ffffffffffffffff
x11: ffff700011ede14c x10: 0000000000ff0100 x9 : 5fa3c1ffaf0ff000
x8 : 5fa3c1ffaf0ff000 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff8000a03a7078 x4 : ffff80008f766c20 x3 : ffff80008054d360
x2 : 0000000000000000 x1 : 0000000000000201 x0 : 0000000000000000
Call trace:
kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955 (P)
cipso_v4_sock_setattr+0x2f0/0x3f4 net/ipv4/cipso_ipv4.c:1914
netlbl_sock_setattr+0x240/0x334 net/netlabel/netlabel_kapi.c:1000
smack_netlbl_add+0xa8/0x158 security/smack/smack_lsm.c:2581
smack_inode_setsecurity+0x378/0x430 security/smack/smack_lsm.c:2912
security_inode_setsecurity+0x118/0x3c0 security/security.c:2706
__vfs_setxattr_noperm+0x174/0x5c4 fs/xattr.c:251
__vfs_setxattr_locked+0x1ec/0x218 fs/xattr.c:295
vfs_setxattr+0x158/0x2ac fs/xattr.c:321
do_setxattr fs/xattr.c:636 [inline]
file_setxattr+0x1b8/0x294 fs/xattr.c:646
path_setxattrat+0x2ac/0x320 fs/xattr.c:711
__do_sys_fsetxattr fs/xattr.c:761 [inline]
__se_sys_fsetxattr fs/xattr.c:758 [inline]
__arm64_sys_fsetxattr+0xc0/0xdc fs/xattr.c:758
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
[1]:
Unable to handle kernel write to read-only memory at virtual address ffff8000891ac9a8
KASAN: probably user-memory-access in range [0x0000000448d64d40-0x0000000448d64d47]
Mem abort info:
ESR = 0x000000009600004e
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x0e: level 2 permission fault
Data abort info:
ISV = 0, ISS = 0x0000004e, ISS2 = 0x00000000
CM = 0, WnR = 1, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000207144000
[ffff8000891ac9a8] pgd=0000000000000000, p4d=100000020f950003, pud=100000020f951003, pmd=0040000201000781
Internal error: Oops: 000000009600004e [#1] SMP
Modules linked in:
CPU: 0 UID: 0 PID: 6946 Comm: syz.0.69 Not tainted 6.16.0-rc4-syzkaller-g7482bb149b9f #0 PREEMPT
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : kvfree_call_rcu+0x31c/0x3f0 mm/slab_common.c:1971
lr : add_ptr_to_bulk_krc_lock mm/slab_common.c:1838 [inline]
lr : kvfree_call_rcu+0xfc/0x3f0 mm/slab_common.c:1963
sp : ffff8000a28a7730
x29: ffff8000a28a7730 x28: 00000000fffffff5 x27: 1fffe00018b09bb3
x26: 0000000000000001 x25: ffff80008f66e000 x24: ffff00019beaf498
x23: ffff00019beaf4c0 x22: 0000000000000000 x21: ffff8000891ac9a0
x20: ffff8000891ac9a0 x19: 0000000000000000 x18: 00000000ffffffff
x17: ffff800093363000 x16: ffff80008052c6e4 x15: ffff700014514ecc
x14: 1ffff00014514ecc x13: 0000000000000004 x12: ffffffffffffffff
x11: ffff700014514ecc x10: 0000000000000001 x9 : 0000000000000001
x8 : ffff00019beaf7b4 x7 : ffff800080a94154 x6 : 0000000000000000
x5 : ffff8000935efa60 x4 : 0000000000000008 x3 : ffff80008052c7fc
x2 : 0000000000000001 x1 : ffff8000891ac9a0 x0 : 0000000000000001
Call trace:
kvfree_call_rcu+0x31c/0x3f0 mm/slab_common.c:1967 (P)
cipso_v4_sock_setattr+0x2f0/0x3f4 net/ipv4/cipso_ipv4.c:1914
netlbl_sock_setattr+0x240/0x334 net/netlabel/netlabel_kapi.c:1000
smack_netlbl_add+0xa8/0x158 security/smack/smack_lsm.c:2581
smack_inode_setsecurity+0x378/0x430 security/smack/smack_lsm.c:2912
security_inode_setsecurity+0x118/0x3c0 security/security.c:2706
__vfs_setxattr_noperm+0x174/0x5c4 fs/xattr.c:251
__vfs_setxattr_locked+0x1ec/0x218 fs/xattr.c:295
vfs_setxattr+0x158/0x2ac fs/xattr.c:321
do_setxattr fs/xattr.c:636 [inline]
file_setxattr+0x1b8/0x294 fs/xattr.c:646
path_setxattrat+0x2ac/0x320 fs/xattr.c:711
__do_sys_fsetxattr fs/xattr.c:761 [inline]
__se_sys_fsetxattr fs/xattr.c:758 [inline]
__arm64_sys_fsetxattr+0xc0/0xdc fs/xattr.c:758
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
Code: aa1f03e2 52800023 97ee1e8d b4000195 (f90006b4)
Fixes: d25a92ccae6b ("net/smc: Introduce IPPROTO_SMC")
Reported-by: syzbot+40bf00346c3fe40f90f2@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/686d9b50.050a0220.1ffab7.0020.GAE@google.com/
Tested-by: syzbot+40bf00346c3fe40f90f2@syzkaller.appspotmail.com
Reported-by: syzbot+f22031fad6cbe52c70e7@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/686da0f3.050a0220.1ffab7.0022.GAE@google.com/
Reported-by: syzbot+271fed3ed6f24600c364@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=271fed3ed6f24600c364 # [2]
Link: https://lore.kernel.org/netdev/99f284be-bf1d-4bc4-a629-77b268522fff@huawei.com/ # [3]
Link: https://lore.kernel.org/netdev/20250331081003.1503211-1-wangliang74@huawei.com/ # [4]
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Wang Liang <wangliang74@huawei.com>
Link: https://patch.msgid.link/20250711060808.2977529-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
SMC consists of two sockets: smc_sock and kernel TCP socket.
Currently, there are two ways of creating the sockets, and syzbot reported
a lockdep splat [0] for the newer way introduced by commit d25a92ccae6b
("net/smc: Introduce IPPROTO_SMC").
socket(AF_SMC , SOCK_STREAM, SMCPROTO_SMC or SMCPROTO_SMC6)
socket(AF_INET or AF_INET6, SOCK_STREAM, IPPROTO_SMC)
When a socket is allocated, sock_lock_init() sets a lockdep lock class to
sk->sk_lock.slock based on its protocol family. In the IPPROTO_SMC case,
AF_INET or AF_INET6 lock class is assigned to smc_sock.
The repro sets IPV6_JOIN_ANYCAST for IPv6 UDP and SMC socket and exercises
smc_switch_to_fallback() for IPPROTO_SMC.
1. smc_switch_to_fallback() is called under lock_sock() and holds
smc->clcsock_release_lock.
sk_lock-AF_INET6 -> &smc->clcsock_release_lock
(sk_lock-AF_SMC)
2. Setting IPV6_JOIN_ANYCAST to SMC holds smc->clcsock_release_lock
and calls setsockopt() for the kernel TCP socket, which holds RTNL
and the kernel socket's lock_sock().
&smc->clcsock_release_lock -> rtnl_mutex (-> k-sk_lock-AF_INET6)
3. Setting IPV6_JOIN_ANYCAST to UDP holds RTNL and lock_sock().
rtnl_mutex -> sk_lock-AF_INET6
Then, lockdep detects a false-positive circular locking,
.-> sk_lock-AF_INET6 -> &smc->clcsock_release_lock -> rtnl_mutex -.
`-----------------------------------------------------------------'
but IPPROTO_SMC should have the same locking rule as AF_SMC.
sk_lock-AF_SMC -> &smc->clcsock_release_lock -> rtnl_mutex -> k-sk_lock-AF_INET6
Let's set the same lock class for smc_sock.
Given AF_SMC uses the same lock class for SMCPROTO_SMC and SMCPROTO_SMC6,
we do not need to separate the class for AF_INET and AF_INET6.
[0]:
WARNING: possible circular locking dependency detected
6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0 Not tainted
syz.4.1528/11571 is trying to acquire lock:
ffffffff8fef8de8 (rtnl_mutex){+.+.}-{4:4}, at: ipv6_sock_ac_close+0xd9/0x110 net/ipv6/anycast.c:220
but task is already holding lock:
ffff888027f596a8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_clcsock_release+0x75/0xe0 net/smc/smc_close.c:30
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&smc->clcsock_release_lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
smc_switch_to_fallback+0x2d/0xa00 net/smc/af_smc.c:903
smc_sendmsg+0x13d/0x520 net/smc/af_smc.c:2781
sock_sendmsg_nosec net/socket.c:718 [inline]
__sock_sendmsg net/socket.c:733 [inline]
____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573
___sys_sendmsg+0x135/0x1e0 net/socket.c:2627
__sys_sendmsg+0x16e/0x220 net/socket.c:2659
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (sk_lock-AF_INET6){+.+.}-{0:0}:
lock_sock_nested+0x3a/0xf0 net/core/sock.c:3645
lock_sock include/net/sock.h:1624 [inline]
sockopt_lock_sock net/core/sock.c:1133 [inline]
sockopt_lock_sock+0x54/0x70 net/core/sock.c:1124
do_ipv6_setsockopt+0x2160/0x4520 net/ipv6/ipv6_sockglue.c:567
ipv6_setsockopt+0xcb/0x170 net/ipv6/ipv6_sockglue.c:993
udpv6_setsockopt+0x7d/0xd0 net/ipv6/udp.c:1850
do_sock_setsockopt+0x222/0x480 net/socket.c:2303
__sys_setsockopt+0x1a0/0x230 net/socket.c:2328
__do_sys_setsockopt net/socket.c:2334 [inline]
__se_sys_setsockopt net/socket.c:2331 [inline]
__x64_sys_setsockopt+0xbd/0x160 net/socket.c:2331
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (rtnl_mutex){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3163 [inline]
check_prevs_add kernel/locking/lockdep.c:3282 [inline]
validate_chain kernel/locking/lockdep.c:3906 [inline]
__lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
ipv6_sock_ac_close+0xd9/0x110 net/ipv6/anycast.c:220
inet6_release+0x47/0x70 net/ipv6/af_inet6.c:485
__sock_release net/socket.c:647 [inline]
sock_release+0x8e/0x1d0 net/socket.c:675
smc_clcsock_release+0xb7/0xe0 net/smc/smc_close.c:34
__smc_release+0x5c2/0x880 net/smc/af_smc.c:301
smc_release+0x1fc/0x5f0 net/smc/af_smc.c:344
__sock_release+0xb0/0x270 net/socket.c:647
sock_close+0x1c/0x30 net/socket.c:1398
__fput+0x3ff/0xb70 fs/file_table.c:464
task_work_run+0x14e/0x250 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
rtnl_mutex --> sk_lock-AF_INET6 --> &smc->clcsock_release_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&smc->clcsock_release_lock);
lock(sk_lock-AF_INET6);
lock(&smc->clcsock_release_lock);
lock(rtnl_mutex);
*** DEADLOCK ***
2 locks held by syz.4.1528/11571:
#0: ffff888077e88208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline]
#0: ffff888077e88208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:646
#1: ffff888027f596a8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_clcsock_release+0x75/0xe0 net/smc/smc_close.c:30
stack backtrace:
CPU: 0 UID: 0 PID: 11571 Comm: syz.4.1528 Not tainted 6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_circular_bug+0x490/0x760 kernel/locking/lockdep.c:2076
check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2208
check_prev_add kernel/locking/lockdep.c:3163 [inline]
check_prevs_add kernel/locking/lockdep.c:3282 [inline]
validate_chain kernel/locking/lockdep.c:3906 [inline]
__lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
ipv6_sock_ac_close+0xd9/0x110 net/ipv6/anycast.c:220
inet6_release+0x47/0x70 net/ipv6/af_inet6.c:485
__sock_release net/socket.c:647 [inline]
sock_release+0x8e/0x1d0 net/socket.c:675
smc_clcsock_release+0xb7/0xe0 net/smc/smc_close.c:34
__smc_release+0x5c2/0x880 net/smc/af_smc.c:301
smc_release+0x1fc/0x5f0 net/smc/af_smc.c:344
__sock_release+0xb0/0x270 net/socket.c:647
sock_close+0x1c/0x30 net/socket.c:1398
__fput+0x3ff/0xb70 fs/file_table.c:464
task_work_run+0x14e/0x250 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b4b38d169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe4efd22d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00000000000b14a3 RCX: 00007f8b4b38d169
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f8b4b5a7ba0 R08: 0000000000000001 R09: 000000114efd25cf
R10: 00007f8b4b200000 R11: 0000000000000246 R12: 00007f8b4b5a5fac
R13: 00007f8b4b5a5fa0 R14: ffffffffffffffff R15: 00007ffe4efd23f0
</TASK>
Fixes: d25a92ccae6b ("net/smc: Introduce IPPROTO_SMC")
Reported-by: syzbot+be6f4b383534d88989f7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=be6f4b383534d88989f7
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Link: https://patch.msgid.link/20250407170332.26959-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When using smc_pnet in SMC, it will only search the pnetid in the
base_ndev of the netdev hierarchy(both HW PNETID and User-defined
sw pnetid). This may not work for some scenarios when using SMC in
container on cloud environment.
In container, there have choices of different container network,
such as directly using host network, virtual network IPVLAN, veth,
etc. Different choices of container network have different netdev
hierarchy. Examples of netdev hierarchy show below. (eth0 and eth1
in host below is the netdev directly related to the physical device).
_______________________________
| _________________ |
| |POD | |
| | | |
| | eth0_________ | |
| |____| |__| |
| | | |
| | | |
| eth1|base_ndev| eth0_______ |
| | | | RDMA ||
| host |_________| |_______||
---------------------------------
netdev hierarchy if directly using host network
________________________________
| _________________ |
| |POD __________ | |
| | |upper_ndev| | |
| |eth0|__________| | |
| |_______|_________| |
| |lower netdev |
| __|______ |
| eth1| | eth0_______ |
| |base_ndev| | RDMA ||
| host |_________| |_______||
---------------------------------
netdev hierarchy if using IPVLAN
_______________________________
| _____________________ |
| |POD _________ | |
| | |base_ndev|| |
| |eth0(veth)|_________|| |
| |____________|________| |
| |pairs |
| _______|_ |
| | | eth0_______ |
| veth|base_ndev| | RDMA ||
| |_________| |_______||
| _________ |
| eth1|base_ndev| |
| host |_________| |
---------------------------------
netdev hierarchy if using veth
Due to some reasons, the eth1 in host is not RDMA attached netdevice,
pnetid is needed to map the eth1(in host) with RDMA device so that POD
can do SMC-R. Because the eth1(in host) is managed by CNI plugin(such
as Terway, network management plugin in container environment), and in
cloud environment the eth(in host) can dynamically be inserted by CNI
when POD create and dynamically be removed by CNI when POD destroy and
no POD related to the eth(in host) anymore. It is hard to config the
pnetid to the eth1(in host). But it is easy to config the pnetid to the
netdevice which can be seen in POD. When do SMC-R, both the container
directly using host network and the container using veth network can
successfully match the RDMA device, because the configured pnetid netdev
is a base_ndev. But the container using IPVLAN can not successfully
match the RDMA device and 0x03030000 fallback happens, because the
configured pnetid netdev is not a base_ndev. Additionally, if config
pnetid to the eth1(in host) also can not work for matching RDMA device
when using veth network and doing SMC-R in POD.
To resolve the problems list above, this patch extends to search user
-defined sw pnetid in the clc handshake ndev when no pnetid can be found
in the base_ndev, and the base_ndev take precedence over ndev for backward
compatibility. This patch also can unify the pnetid setup of different
network choices list above in container(Config user-defined sw pnetid in
the netdevice can be seen in POD).
Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While kernel sockets are dismantled during pernet_operations->exit(),
their freeing can be delayed by any tx packets still held in qdisc
or device queues, due to skb_set_owner_w() prior calls.
This then trigger the following warning from ref_tracker_dir_exit() [1]
To fix this, make sure that kernel sockets own a reference on net->passive.
Add sk_net_refcnt_upgrade() helper, used whenever a kernel socket
is converted to a refcounted one.
[1]
[ 136.263918][ T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at
[ 136.263918][ T35] sk_alloc+0x2b3/0x370
[ 136.263918][ T35] inet6_create+0x6ce/0x10f0
[ 136.263918][ T35] __sock_create+0x4c0/0xa30
[ 136.263918][ T35] inet_ctl_sock_create+0xc2/0x250
[ 136.263918][ T35] igmp6_net_init+0x39/0x390
[ 136.263918][ T35] ops_init+0x31e/0x590
[ 136.263918][ T35] setup_net+0x287/0x9e0
[ 136.263918][ T35] copy_net_ns+0x33f/0x570
[ 136.263918][ T35] create_new_namespaces+0x425/0x7b0
[ 136.263918][ T35] unshare_nsproxy_namespaces+0x124/0x180
[ 136.263918][ T35] ksys_unshare+0x57d/0xa70
[ 136.263918][ T35] __x64_sys_unshare+0x38/0x40
[ 136.263918][ T35] do_syscall_64+0xf3/0x230
[ 136.263918][ T35] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 136.263918][ T35]
[ 136.343488][ T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at
[ 136.343488][ T35] sk_alloc+0x2b3/0x370
[ 136.343488][ T35] inet6_create+0x6ce/0x10f0
[ 136.343488][ T35] __sock_create+0x4c0/0xa30
[ 136.343488][ T35] inet_ctl_sock_create+0xc2/0x250
[ 136.343488][ T35] ndisc_net_init+0xa7/0x2b0
[ 136.343488][ T35] ops_init+0x31e/0x590
[ 136.343488][ T35] setup_net+0x287/0x9e0
[ 136.343488][ T35] copy_net_ns+0x33f/0x570
[ 136.343488][ T35] create_new_namespaces+0x425/0x7b0
[ 136.343488][ T35] unshare_nsproxy_namespaces+0x124/0x180
[ 136.343488][ T35] ksys_unshare+0x57d/0xa70
[ 136.343488][ T35] __x64_sys_unshare+0x38/0x40
[ 136.343488][ T35] do_syscall_64+0xf3/0x230
[ 136.343488][ T35] entry_SYSCALL_64_after_hwframe+0x77/0x7f
Fixes: 0cafd77dcd03 ("net: add a refcount tracker for kernel sockets")
Reported-by: syzbot+30a19e01a97420719891@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/67b72aeb.050a0220.14d86d.0283.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250220131854.4048077-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When recvmsg with MSG_PEEK flag, the data will be copied to
user's buffer without advancing consume cursor and without
reducing the length of rx available data. Once the expected
peek length is larger than the value of bytes_to_rcv, in the
loop of do while in smc_rx_recvmsg, the first loop will copy
bytes_to_rcv bytes of data from the position local_tx_ctrl.cons,
the second loop will copy the min(bytes_to_rcv, read_remaining)
bytes from the position local_tx_ctrl.cons again because of the
lacking of process with advancing consume cursor and reducing
the length of available data. So do the subsequent loops. The
data copied in the second loop and the subsequent loops will
result in data error, as it should not be copied if no more data
arrives and it should be copied from the position advancing
bytes_to_rcv bytes from the local_tx_ctrl.cons if more data arrives.
This issue can be reproduce by the following python script:
server.py:
import socket
import time
server_ip = '0.0.0.0'
server_port = 12346
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.bind((server_ip, server_port))
server_socket.listen(1)
print('Server is running and listening for connections...')
conn, addr = server_socket.accept()
print('Connected by', addr)
while True:
data = conn.recv(1024)
if not data:
break
print('Received request:', data.decode())
conn.sendall(b'Hello, client!\n')
time.sleep(5)
conn.sendall(b'Hello, again!\n')
conn.close()
client.py:
import socket
server_ip = '<server ip>'
server_port = 12346
resp=b'Hello, client!\nHello, again!\n'
client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client_socket.connect((server_ip, server_port))
request = 'Hello, server!'
client_socket.sendall(request.encode())
peek_data = client_socket.recv(len(resp),
socket.MSG_PEEK | socket.MSG_WAITALL)
print('Peeked data:', peek_data.decode())
client_socket.close()
Fixes: 952310ccf2d8 ("smc: receive data from RMBE")
Reported-by: D. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Link: https://patch.msgid.link/20250104143201.35529-1-guangguan.wang@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>