[PATCH 5.4 08/34] RDMA/core: Dont infoleak GRH fields
From: Greg Kroah-Hartman
Date: Mon Jan 10 2022 - 02:39:32 EST
From: Leon Romanovsky <leonro@xxxxxxxxxx>
commit b35a0f4dd544eaa6162b6d2f13a2557a121ae5fd upstream.
If dst->is_global field is not set, the GRH fields are not cleared
and the following infoleak is reported.
=====================================================
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0x1c9/0x270 lib/usercopy.c:33
instrument_copy_to_user include/linux/instrumented.h:121 [inline]
_copy_to_user+0x1c9/0x270 lib/usercopy.c:33
copy_to_user include/linux/uaccess.h:209 [inline]
ucma_init_qp_attr+0x8c7/0xb10 drivers/infiniband/core/ucma.c:1242
ucma_write+0x637/0x6c0 drivers/infiniband/core/ucma.c:1732
vfs_write+0x8ce/0x2030 fs/read_write.c:588
ksys_write+0x28b/0x510 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__ia32_sys_write+0xdb/0x120 fs/read_write.c:652
do_syscall_32_irqs_on arch/x86/entry/common.c:114 [inline]
__do_fast_syscall_32+0x96/0xf0 arch/x86/entry/common.c:180
do_fast_syscall_32+0x34/0x70 arch/x86/entry/common.c:205
do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:248
entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
Local variable resp created at:
ucma_init_qp_attr+0xa4/0xb10 drivers/infiniband/core/ucma.c:1214
ucma_write+0x637/0x6c0 drivers/infiniband/core/ucma.c:1732
Bytes 40-59 of 144 are uninitialized
Memory access of size 144 starts at ffff888167523b00
Data copied to user address 0000000020000100
CPU: 1 PID: 25910 Comm: syz-executor.1 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
=====================================================
Fixes: 4ba66093bdc6 ("IB/core: Check for global flag when using ah_attr")
Link: https://lore.kernel.org/r/0e9dd51f93410b7b2f4f5562f52befc878b71afa.1641298868.git.leonro@xxxxxxxxxx
Reported-by: syzbot+6d532fa8f9463da290bc@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/infiniband/core/uverbs_marshall.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/infiniband/core/uverbs_marshall.c
+++ b/drivers/infiniband/core/uverbs_marshall.c
@@ -66,7 +66,7 @@ void ib_copy_ah_attr_to_user(struct ib_d
struct rdma_ah_attr *src = ah_attr;
struct rdma_ah_attr conv_ah;
- memset(&dst->grh.reserved, 0, sizeof(dst->grh.reserved));
+ memset(&dst->grh, 0, sizeof(dst->grh));
if ((ah_attr->type == RDMA_AH_ATTR_TYPE_OPA) &&
(rdma_ah_get_dlid(ah_attr) > be16_to_cpu(IB_LID_PERMISSIVE)) &&