| Message ID | 20200418062602.10776-1-kuhn.chenqun@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | block/iscsi:fix heap-buffer-overflow in iscsi_aio_ioctl_cb | expand |
diff --git a/block/iscsi.c b/block/iscsi.c index 4e216bd8aa..0b4b7210df 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); }
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> --- v1->v2: Use MIN() macro for mx_sb_len and sb_len_wr. (Base comments from Michael S. Tsirkin, Stefan Hajnoczi, Kevin Wolf) Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Kevin Wolf <kwolf@redhat.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Prasad J Pandit <ppandit@redhat.com> Cc: Max Reitz <mreitz@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Lieven <pl@kamp.de> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: qemu-block@nongnu.org --- block/iscsi.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)