File block-iscsi-fix-heap-buffer-overflow-in-.patch of Package qemu.28164
From: Chen Qun <kuhn.chenqun@huawei.com>
Date: Sat, 18 Apr 2020 14:26:02 +0800
Subject: block/iscsi:fix heap-buffer-overflow in iscsi_aio_ioctl_cb
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Git-commit: ff0507c239a246fd7215b31c5658fc6a3ee1e4c5
References: bsc#1180523, CVE-2020-11947
There is an overflow, the source 'datain.data[2]' is 100 bytes,
but the 'ss' is 252 bytes.This may cause a security issue because
we can access a lot of unrelated memory data.
The len for sbp copy data should take the minimum of mx_sb_len and
sb_len_wr, not the maximum.
If we use iscsi device for VM backend storage, ASAN show stack:
READ of size 252 at 0xfffd149dcfc4 thread T0
#0 0xaaad433d0d34 in __asan_memcpy (aarch64-softmmu/qemu-system-aarch64+0x2cb0d34)
#1 0xaaad45f9d6d0 in iscsi_aio_ioctl_cb /qemu/block/iscsi.c:996:9
#2 0xfffd1af0e2dc (/usr/lib64/iscsi/libiscsi.so.8+0xe2dc)
#3 0xfffd1af0d174 (/usr/lib64/iscsi/libiscsi.so.8+0xd174)
#4 0xfffd1af19fac (/usr/lib64/iscsi/libiscsi.so.8+0x19fac)
#5 0xaaad45f9acc8 in iscsi_process_read /qemu/block/iscsi.c:403:5
#6 0xaaad4623733c in aio_dispatch_handler /qemu/util/aio-posix.c:467:9
#7 0xaaad4622f350 in aio_dispatch_handlers /qemu/util/aio-posix.c:510:20
#8 0xaaad4622f350 in aio_dispatch /qemu/util/aio-posix.c:520
#9 0xaaad46215944 in aio_ctx_dispatch /qemu/util/async.c:298:5
#10 0xfffd1bed12f4 in g_main_context_dispatch (/lib64/libglib-2.0.so.0+0x512f4)
#11 0xaaad46227de0 in glib_pollfds_poll /qemu/util/main-loop.c:219:9
#12 0xaaad46227de0 in os_host_main_loop_wait /qemu/util/main-loop.c:242
#13 0xaaad46227de0 in main_loop_wait /qemu/util/main-loop.c:518
#14 0xaaad43d9d60c in qemu_main_loop /qemu/softmmu/vl.c:1662:9
#15 0xaaad4607a5b0 in main /qemu/softmmu/main.c:49:5
#16 0xfffd1a460b9c in __libc_start_main (/lib64/libc.so.6+0x20b9c)
#17 0xaaad43320740 in _start (aarch64-softmmu/qemu-system-aarch64+0x2c00740)
0xfffd149dcfc4 is located 0 bytes to the right of 100-byte region [0xfffd149dcf60,0xfffd149dcfc4)
allocated by thread T0 here:
#0 0xaaad433d1e70 in __interceptor_malloc (aarch64-softmmu/qemu-system-aarch64+0x2cb1e70)
#1 0xfffd1af0e254 (/usr/lib64/iscsi/libiscsi.so.8+0xe254)
#2 0xfffd1af0d174 (/usr/lib64/iscsi/libiscsi.so.8+0xd174)
#3 0xfffd1af19fac (/usr/lib64/iscsi/libiscsi.so.8+0x19fac)
#4 0xaaad45f9acc8 in iscsi_process_read /qemu/block/iscsi.c:403:5
#5 0xaaad4623733c in aio_dispatch_handler /qemu/util/aio-posix.c:467:9
#6 0xaaad4622f350 in aio_dispatch_handlers /qemu/util/aio-posix.c:510:20
#7 0xaaad4622f350 in aio_dispatch /qemu/util/aio-posix.c:520
#8 0xaaad46215944 in aio_ctx_dispatch /qemu/util/async.c:298:5
#9 0xfffd1bed12f4 in g_main_context_dispatch (/lib64/libglib-2.0.so.0+0x512f4)
#10 0xaaad46227de0 in glib_pollfds_poll /qemu/util/main-loop.c:219:9
#11 0xaaad46227de0 in os_host_main_loop_wait /qemu/util/main-loop.c:242
#12 0xaaad46227de0 in main_loop_wait /qemu/util/main-loop.c:518
#13 0xaaad43d9d60c in qemu_main_loop /qemu/softmmu/vl.c:1662:9
#14 0xaaad4607a5b0 in main /qemu/softmmu/main.c:49:5
#15 0xfffd1a460b9c in __libc_start_main (/lib64/libc.so.6+0x20b9c)
#16 0xaaad43320740 in _start (aarch64-softmmu/qemu-system-aarch64+0x2c00740)
Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200418062602.10776-1-kuhn.chenqun@huawei.com
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
block/iscsi.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/block/iscsi.c b/block/iscsi.c
index cbd57294ab4417a33657af0fbce8..3a528c15ec9e17386569f604df86 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -991,8 +991,7 @@ iscsi_aio_ioctl_cb(struct iscsi_context *iscsi, int status,
acb->ioh->driver_status |= SG_ERR_DRIVER_SENSE;
acb->ioh->sb_len_wr = acb->task->datain.size - 2;
- ss = (acb->ioh->mx_sb_len >= acb->ioh->sb_len_wr) ?
- acb->ioh->mx_sb_len : acb->ioh->sb_len_wr;
+ ss = MIN(acb->ioh->mx_sb_len, acb->ioh->sb_len_wr);
memcpy(acb->ioh->sbp, &acb->task->datain.data[2], ss);
}
