| Age | Commit message (Collapse) | Author | Files | Lines |
|---|
|
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>
|
|
The smcd_ops->supports_v2 is only called in smcd_register_dev(), which
calls function smcd_supports_v2 for ism. For loopback-ism, function
smc_lo_supports_v2 is unused, remove it.
Signed-off-by: Wang Liang <wangliang74@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250619030854.1536676-1-wangliang74@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
This implements operations related to merging sndbuf with peer DMB in
loopback-ism. The DMB won't be freed until no sndbuf is attached to it.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-and-tested-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
After the loopback-ism device is ready, add it to the SMC-D device list
as an ISMv2 device, and always keep it at the beginning to ensure it is
preferred for providing a shortcut for data transfer within the same
kernel.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-and-tested-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
This implements DMB (un)registration and data move operations of
loopback-ism device.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-and-tested-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
This implements operations related to IDs for the loopback-ism device.
loopback-ism uses an Extended GID that is a 128-bit GID instead of the
existing ISM 64-bit GID, and uses the CHID defined with the reserved
value 0xFFFF.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-and-tested-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
This introduces a kind of Emulated-ISM device named loopback-ism for
SMCv2.1. The loopback-ism device is currently exclusive for SMC usage,
and aims to provide an SMC shortcut for sockets within the same kernel,
leading to improved intra-OS traffic performance. Configuration of this
feature is managed through the config SMC_LO.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-and-tested-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
