[PATCH openEuler-1.0-LTS 1/2] scsi: scsi_debug: Fix out-of-bound read in resp_readcap16()
From: Ye Bin yebin10@huawei.com
mainline inclusion from mainline-v5.16 commit 4e3ace0051e7e504b55d239daab8789dd89b863c category: bugfix bugzilla: 176010 CVE: NA
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The following warning was observed running syzkaller:
[ 3813.830724] sg_write: data in/out 65466/242 bytes for SCSI command 0x9e-- guessing data in; [ 3813.830724] program syz-executor not setting count and/or reply_len properly [ 3813.836956] ================================================================== [ 3813.839465] BUG: KASAN: stack-out-of-bounds in sg_copy_buffer+0x157/0x1e0 [ 3813.841773] Read of size 4096 at addr ffff8883cf80f540 by task syz-executor/1549 [ 3813.846612] Call Trace: [ 3813.846995] dump_stack+0x108/0x15f [ 3813.847524] print_address_description+0xa5/0x372 [ 3813.848243] kasan_report.cold+0x236/0x2a8 [ 3813.849439] check_memory_region+0x240/0x270 [ 3813.850094] memcpy+0x30/0x80 [ 3813.850553] sg_copy_buffer+0x157/0x1e0 [ 3813.853032] sg_copy_from_buffer+0x13/0x20 [ 3813.853660] fill_from_dev_buffer+0x135/0x370 [ 3813.854329] resp_readcap16+0x1ac/0x280 [ 3813.856917] schedule_resp+0x41f/0x1630 [ 3813.858203] scsi_debug_queuecommand+0xb32/0x17e0 [ 3813.862699] scsi_dispatch_cmd+0x330/0x950 [ 3813.863329] scsi_request_fn+0xd8e/0x1710 [ 3813.863946] __blk_run_queue+0x10b/0x230 [ 3813.864544] blk_execute_rq_nowait+0x1d8/0x400 [ 3813.865220] sg_common_write.isra.0+0xe61/0x2420 [ 3813.871637] sg_write+0x6c8/0xef0 [ 3813.878853] __vfs_write+0xe4/0x800 [ 3813.883487] vfs_write+0x17b/0x530 [ 3813.884008] ksys_write+0x103/0x270 [ 3813.886268] __x64_sys_write+0x77/0xc0 [ 3813.886841] do_syscall_64+0x106/0x360 [ 3813.887415] entry_SYSCALL_64_after_hwframe+0x44/0xa9
This issue can be reproduced with the following syzkaller log:
r0 = openat(0xffffffffffffff9c, &(0x7f0000000040)='./file0\x00', 0x26e1, 0x0) r1 = syz_open_procfs(0xffffffffffffffff, &(0x7f0000000000)='fd/3\x00') open_by_handle_at(r1, &(0x7f00000003c0)=ANY=[@ANYRESHEX], 0x602000) r2 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x40782) write$binfmt_aout(r2, &(0x7f0000000340)=ANY=[@ANYBLOB="00000000deff000000000000000000000000000000000000000000000000000047f007af9e107a41ec395f1bded7be24277a1501ff6196a83366f4e6362bc0ff2b247f68a972989b094b2da4fb3607fcf611a22dd04310d28c75039d"], 0x126)
In resp_readcap16() we get "int alloc_len" value -1104926854, and then pass the huge arr_len to fill_from_dev_buffer(), but arr is only 32 bytes. This leads to OOB in sg_copy_buffer().
To solve this issue, define alloc_len as u32.
Link: https://lore.kernel.org/r/20211013033913.2551004-2-yebin10@huawei.com Acked-by: Douglas Gilbert dgilbert@interlog.com Signed-off-by: Ye Bin yebin10@huawei.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com
conflicts: drivers/scsi/scsi_debug.c
Signed-off-by: Ye Bin yebin10@huawei.com Reviewed-by: Jason Yan yanaijie@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/scsi/scsi_debug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index 082b2695e02f3..d8befc6fbec9c 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -1665,7 +1665,7 @@ static int resp_readcap16(struct scsi_cmnd *scp, { unsigned char *cmd = scp->cmnd; unsigned char arr[SDEBUG_READCAP16_ARR_SZ]; - int alloc_len; + u32 alloc_len;
alloc_len = get_unaligned_be32(cmd + 10); /* following just in case virtual_gb changed */ @@ -1694,7 +1694,7 @@ static int resp_readcap16(struct scsi_cmnd *scp, }
return fill_from_dev_buffer(scp, arr, - min(alloc_len, SDEBUG_READCAP16_ARR_SZ)); + min_t(u32, alloc_len, SDEBUG_READCAP16_ARR_SZ)); }
#define SDEBUG_MAX_TGTPGS_ARR_SZ 1412
From: Ye Bin yebin10@huawei.com
mainline inclusion from mainline-v5.16 commit f347c26836c270199de1599c3cd466bb7747caa9 category: bugfix bugzilla: 176010 CVE: NA
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The following issue was observed running syzkaller:
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:377 [inline] BUG: KASAN: slab-out-of-bounds in sg_copy_buffer+0x150/0x1c0 lib/scatterlist.c:831 Read of size 2132 at addr ffff8880aea95dc8 by task syz-executor.0/9815
CPU: 0 PID: 9815 Comm: syz-executor.0 Not tainted 4.19.202-00874-gfc0fe04215a9 #2 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+0xe4/0x14a lib/dump_stack.c:118 print_address_description+0x73/0x280 mm/kasan/report.c:253 kasan_report_error mm/kasan/report.c:352 [inline] kasan_report+0x272/0x370 mm/kasan/report.c:410 memcpy+0x1f/0x50 mm/kasan/kasan.c:302 memcpy include/linux/string.h:377 [inline] sg_copy_buffer+0x150/0x1c0 lib/scatterlist.c:831 fill_from_dev_buffer+0x14f/0x340 drivers/scsi/scsi_debug.c:1021 resp_report_tgtpgs+0x5aa/0x770 drivers/scsi/scsi_debug.c:1772 schedule_resp+0x464/0x12f0 drivers/scsi/scsi_debug.c:4429 scsi_debug_queuecommand+0x467/0x1390 drivers/scsi/scsi_debug.c:5835 scsi_dispatch_cmd+0x3fc/0x9b0 drivers/scsi/scsi_lib.c:1896 scsi_request_fn+0x1042/0x1810 drivers/scsi/scsi_lib.c:2034 __blk_run_queue_uncond block/blk-core.c:464 [inline] __blk_run_queue+0x1a4/0x380 block/blk-core.c:484 blk_execute_rq_nowait+0x1c2/0x2d0 block/blk-exec.c:78 sg_common_write.isra.19+0xd74/0x1dc0 drivers/scsi/sg.c:847 sg_write.part.23+0x6e0/0xd00 drivers/scsi/sg.c:716 sg_write+0x64/0xa0 drivers/scsi/sg.c:622 __vfs_write+0xed/0x690 fs/read_write.c:485 kill_bdev:block_device:00000000e138492c vfs_write+0x184/0x4c0 fs/read_write.c:549 ksys_write+0x107/0x240 fs/read_write.c:599 do_syscall_64+0xc2/0x560 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe
We get 'alen' from command its type is int. If userspace passes a large length we will get a negative 'alen'.
Switch n, alen, and rlen to u32.
Link: https://lore.kernel.org/r/20211013033913.2551004-3-yebin10@huawei.com Acked-by: Douglas Gilbert dgilbert@interlog.com Signed-off-by: Ye Bin yebin10@huawei.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com
conflicts: drivers/scsi/scsi_debug.c
Signed-off-by: Ye Bin yebin10@huawei.com Reviewed-by: Jason Yan yanaijie@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/scsi/scsi_debug.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index d8befc6fbec9c..f283905e910f6 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -1705,8 +1705,9 @@ static int resp_report_tgtpgs(struct scsi_cmnd *scp, unsigned char *cmd = scp->cmnd; unsigned char *arr; int host_no = devip->sdbg_host->shost->host_no; - int n, ret, alen, rlen; int port_group_a, port_group_b, port_a, port_b; + u32 alen, n, rlen; + int ret;
alen = get_unaligned_be32(cmd + 6); arr = kzalloc(SDEBUG_MAX_TGTPGS_ARR_SZ, GFP_ATOMIC); @@ -1770,7 +1771,7 @@ static int resp_report_tgtpgs(struct scsi_cmnd *scp, */ rlen = min(alen,n); ret = fill_from_dev_buffer(scp, arr, - min(rlen, SDEBUG_MAX_TGTPGS_ARR_SZ)); + min_t(u32, rlen, SDEBUG_MAX_TGTPGS_ARR_SZ)); kfree(arr); return ret; }
-
Yang Yingliang