[PATCH] scsi: qedi: remove memset/memcpy to nfunc and use func instead

Yue Haibing
2019-04-20T04:05:54Z

From: YueHaibing <yuehaibing@huawei.com>

KASAN report this:

BUG: KASAN: global-out-of-bounds in qedi_dbg_err+0xda/0x330 [qedi]
Read of size 31 at addr ffffffffc12b0ae0 by task syz-executor.0/2429

CPU: 0 PID: 2429 Comm: syz-executor.0 Not tainted 5.0.0-rc7+ #45
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xfa/0x1ce lib/dump_stack.c:113
print_address_description+0x1c4/0x270 mm/kasan/report.c:187
kasan_report+0x149/0x18d mm/kasan/report.c:317
memcpy+0x1f/0x50 mm/kasan/common.c:130
qedi_dbg_err+0xda/0x330 [qedi]
? 0xffffffffc12d0000
qedi_init+0x118/0x1000 [qedi]
? 0xffffffffc12d0000
? 0xffffffffc12d0000
? 0xffffffffc12d0000
do_one_initcall+0xfa/0x5ca init/main.c:887
do_init_module+0x204/0x5f6 kernel/module.c:3460
load_module+0x66b2/0x8570 kernel/module.c:3808
__do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902
do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x462e99
Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2d57e55c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
RAX: ffffffffffffffda RBX: 000000000073bfa0 RCX: 0000000000462e99
RDX: 0000000000000000 RSI: 00000000200003c0 RDI: 0000000000000003
RBP: 00007f2d57e55c70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2d57e566bc
R13: 00000000004bcefb R14: 00000000006f7030 R15: 0000000000000004

The buggy address belongs to the variable:
__func__.67584+0x0/0xffffffffffffd520 [qedi]

Memory state around the buggy address:
ffffffffc12b0980: fa fa fa fa 00 04 fa fa fa fa fa fa 00 00 05 fa
ffffffffc12b0a00: fa fa fa fa 00 00 04 fa fa fa fa fa 00 05 fa fa
> ffffffffc12b0a80: fa fa fa fa 00 06 fa fa fa fa fa fa 00 02 fa fa
^
ffffffffc12b0b00: fa fa fa fa 00 00 04 fa fa fa fa fa 00 00 03 fa
ffffffffc12b0b80: fa fa fa fa 00 00 02 fa fa fa fa fa 00 00 04 fa

Currently the qedi_dbg_* family of functions can overrun the end
of the source string if it is less than the destination buffer
length because of the use of a fixed sized memcpy. Remove the
memset/memcpy calls to nfunc and just use func instead as it
is always a null terminated string.

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: ace7f46ba5fd ("scsi: qedi: Add QLogic FastLinQ offload iSCSI driver framework.")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
---
drivers/scsi/qedi/qedi_dbg.c | 32 ++++++++------------------------
1 file changed, 8 insertions(+), 24 deletions(-)

diff --git a/drivers/scsi/qedi/qedi_dbg.c b/drivers/scsi/qedi/qedi_dbg.c
index 8fd28b0..3383314 100644
--- a/drivers/scsi/qedi/qedi_dbg.c
+++ b/drivers/scsi/qedi/qedi_dbg.c
@@ -16,10 +16,6 @@ qedi_dbg_err(struct qedi_dbg_ctx *qedi, const char *func, u32 line,
{
va_list va;
struct va_format vaf;
- char nfunc[32];
-
- memset(nfunc, 0, sizeof(nfunc));
- memcpy(nfunc, func, sizeof(nfunc) - 1);

va_start(va, fmt);

@@ -28,9 +24,9 @@ qedi_dbg_err(struct qedi_dbg_ctx *qedi, const char *func, u32 line,

if (likely(qedi) && likely(qedi->pdev))
pr_err("[%s]:[%s:%d]:%d: %pV", dev_name(&qedi->pdev->dev),
- nfunc, line, qedi->host_no, &vaf);
+ func, line, qedi->host_no, &vaf);
else
- pr_err("[0000:00:00.0]:[%s:%d]: %pV", nfunc, line, &vaf);
+ pr_err("[0000:00:00.0]:[%s:%d]: %pV", func, line, &vaf);

va_end(va);
}
@@ -41,10 +37,6 @@ qedi_dbg_warn(struct qedi_dbg_ctx *qedi, const char *func, u32 line,
{
va_list va;
struct va_format vaf;
- char nfunc[32];
-
- memset(nfunc, 0, sizeof(nfunc));
- memcpy(nfunc, func, sizeof(nfunc) - 1);

va_start(va, fmt);

@@ -56,9 +48,9 @@ qedi_dbg_warn(struct qedi_dbg_ctx *qedi, const char *func, u32 line,

if (likely(qedi) && likely(qedi->pdev))
pr_warn("[%s]:[%s:%d]:%d: %pV", dev_name(&qedi->pdev->dev),
- nfunc, line, qedi->host_no, &vaf);
+ func, line, qedi->host_no, &vaf);
else
- pr_warn("[0000:00:00.0]:[%s:%d]: %pV", nfunc, line, &vaf);
+ pr_warn("[0000:00:00.0]:[%s:%d]: %pV", func, line, &vaf);

ret:
va_end(va);
@@ -70,10 +62,6 @@ qedi_dbg_notice(struct qedi_dbg_ctx *qedi, const char *func, u32 line,
{
va_list va;
struct va_format vaf;
- char nfunc[32];
-
- memset(nfunc, 0, sizeof(nfunc));
- memcpy(nfunc, func, sizeof(nfunc) - 1);

va_start(va, fmt);

@@ -85,10 +73,10 @@ qedi_dbg_notice(struct qedi_dbg_ctx *qedi, const char *func, u32 line,

if (likely(qedi) && likely(qedi->pdev))
pr_notice("[%s]:[%s:%d]:%d: %pV",
- dev_name(&qedi->pdev->dev), nfunc, line,
+ dev_name(&qedi->pdev->dev), func, line,
qedi->host_no, &vaf);
else
- pr_notice("[0000:00:00.0]:[%s:%d]: %pV", nfunc, line, &vaf);
+ pr_notice("[0000:00:00.0]:[%s:%d]: %pV", func, line, &vaf);

ret:
va_end(va);
@@ -100,10 +88,6 @@ qedi_dbg_info(struct qedi_dbg_ctx *qedi, const char *func, u32 line,
{
va_list va;
struct va_format vaf;
- char nfunc[32];
-
- memset(nfunc, 0, sizeof(nfunc));
- memcpy(nfunc, func, sizeof(nfunc) - 1);

va_start(va, fmt);

@@ -115,9 +99,9 @@ qedi_dbg_info(struct qedi_dbg_ctx *qedi, const char *func, u32 line,

if (likely(qedi) && likely(qedi->pdev))
pr_info("[%s]:[%s:%d]:%d: %pV", dev_name(&qedi->pdev->dev),
- nfunc, line, qedi->host_no, &vaf);
+ func, line, qedi->host_no, &vaf);
else
- pr_info("[0000:00:00.0]:[%s:%d]: %pV", nfunc, line, &vaf);
+ pr_info("[0000:00:00.0]:[%s:%d]: %pV", func, line, &vaf);

ret:
va_end(va);
--
2.7.0