APPLIED: [SRU][F][PATCH 0/1] CVE-2021-47219

[Koichiro Den]

On Mon, Feb 10, 2025 at 04:08:06PM GMT, Ian Whitfield wrote:
> [Impact]
> 
> 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.
> 
> [Backport]
> 
> There was one conflict due to missing a large feature patch, but the
> conflict was unrelated to the missing feature and was for the most
> part a no-op difference. It was resolved by leaving the patch unmodified
> and overwriting that section of the function.
> 
> [Fix]
> 
> Oracular:	not affected
> Noble:		not affected
> Jammy:		not affected
> Focal:		backport
> Bionic:		sent to ESM ML
> Xenial:		sent to ESM ML
> Trusty:		won't fix
> 
> [Test Case]
> 
> Compile and boot tested
> 
> [Where problems could occur]
> 
> This fix affects those who use the SCSI debugging host and device
> simulator. An issue with this fix would be visible to the user as an out
> of bounds memory read.
> 
> Ye Bin (1):
>   scsi: scsi_debug: Fix out-of-bound read in resp_report_tgtpgs()
> 
>  drivers/scsi/scsi_debug.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 

Applied to focal:linux master-next branch. Thanks!