<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/drivers/ata/libata-scsi.c, branch linux-4.9.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-4.9.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-4.9.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2020-09-12T09:47:37Z</updated>
<entry>
<title>libata: implement ATA_HORKAGE_MAX_TRIM_128M and apply to Sandisks</title>
<updated>2020-09-12T09:47:37Z</updated>
<author>
<name>Tejun Heo</name>
</author>
<published>2020-09-02T16:32:45Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=8c36cde29ad1e563def83c41094a96027b7a9b1b'/>
<id>urn:sha1:8c36cde29ad1e563def83c41094a96027b7a9b1b</id>
<content type='text'>
commit 3b5455636fe26ea21b4189d135a424a6da016418 upstream.

All three generations of Sandisk SSDs lock up hard intermittently.
Experiments showed that disabling NCQ lowered the failure rate significantly
and the kernel has been disabling NCQ for some models of SD7's and 8's,
which is obviously undesirable.

Karthik worked with Sandisk to root cause the hard lockups to trim commands
larger than 128M. This patch implements ATA_HORKAGE_MAX_TRIM_128M which
limits max trim size to 128M and applies it to all three generations of
Sandisk SSDs.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Karthik Shivaram &lt;karthikgs@fb.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>ata/libata: Fix usage of page address by page_address in ata_scsi_mode_select_xlat function</title>
<updated>2020-06-30T19:38:43Z</updated>
<author>
<name>Ye Bin</name>
</author>
<published>2020-06-05T01:41:49Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=5fef1b319466387f7dafa89879c90d03919286c9'/>
<id>urn:sha1:5fef1b319466387f7dafa89879c90d03919286c9</id>
<content type='text'>
[ Upstream commit f650ef61e040bcb175dd8762164b00a5d627f20e ]

BUG: KASAN: use-after-free in ata_scsi_mode_select_xlat+0x10bd/0x10f0
drivers/ata/libata-scsi.c:4045
Read of size 1 at addr ffff88803b8cd003 by task syz-executor.6/12621

CPU: 1 PID: 12621 Comm: syz-executor.6 Not tainted 4.19.95 #1
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+0xac/0xee lib/dump_stack.c:118
print_address_description+0x60/0x223 mm/kasan/report.c:253
kasan_report_error mm/kasan/report.c:351 [inline]
kasan_report mm/kasan/report.c:409 [inline]
kasan_report.cold+0xae/0x2d8 mm/kasan/report.c:393
ata_scsi_mode_select_xlat+0x10bd/0x10f0 drivers/ata/libata-scsi.c:4045
ata_scsi_translate+0x2da/0x680 drivers/ata/libata-scsi.c:2035
__ata_scsi_queuecmd drivers/ata/libata-scsi.c:4360 [inline]
ata_scsi_queuecmd+0x2e4/0x790 drivers/ata/libata-scsi.c:4409
scsi_dispatch_cmd+0x2ee/0x6c0 drivers/scsi/scsi_lib.c:1867
scsi_queue_rq+0xfd7/0x1990 drivers/scsi/scsi_lib.c:2170
blk_mq_dispatch_rq_list+0x1e1/0x19a0 block/blk-mq.c:1186
blk_mq_do_dispatch_sched+0x147/0x3d0 block/blk-mq-sched.c:108
blk_mq_sched_dispatch_requests+0x427/0x680 block/blk-mq-sched.c:204
__blk_mq_run_hw_queue+0xbc/0x200 block/blk-mq.c:1308
__blk_mq_delay_run_hw_queue+0x3c0/0x460 block/blk-mq.c:1376
blk_mq_run_hw_queue+0x152/0x310 block/blk-mq.c:1413
blk_mq_sched_insert_request+0x337/0x6c0 block/blk-mq-sched.c:397
blk_execute_rq_nowait+0x124/0x320 block/blk-exec.c:64
blk_execute_rq+0xc5/0x112 block/blk-exec.c:101
sg_scsi_ioctl+0x3b0/0x6a0 block/scsi_ioctl.c:507
sg_ioctl+0xd37/0x23f0 drivers/scsi/sg.c:1106
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xae6/0x1030 fs/ioctl.c:688
ksys_ioctl+0x76/0xa0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
do_syscall_64+0xa0/0x2e0 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c479
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 &lt;48&gt; 3d 01 f0 ff
ff 0f
83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fb0e9602c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb0e96036d4 RCX: 000000000045c479
RDX: 0000000020000040 RSI: 0000000000000001 RDI: 0000000000000003
RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000046d R14: 00000000004c6e1a R15: 000000000076bfcc

Allocated by task 12577:
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc mm/kasan/kasan.c:553 [inline]
kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531
__kmalloc+0xf3/0x1e0 mm/slub.c:3749
kmalloc include/linux/slab.h:520 [inline]
load_elf_phdrs+0x118/0x1b0 fs/binfmt_elf.c:441
load_elf_binary+0x2de/0x4610 fs/binfmt_elf.c:737
search_binary_handler fs/exec.c:1654 [inline]
search_binary_handler+0x15c/0x4e0 fs/exec.c:1632
exec_binprm fs/exec.c:1696 [inline]
__do_execve_file.isra.0+0xf52/0x1a90 fs/exec.c:1820
do_execveat_common fs/exec.c:1866 [inline]
do_execve fs/exec.c:1883 [inline]
__do_sys_execve fs/exec.c:1964 [inline]
__se_sys_execve fs/exec.c:1959 [inline]
__x64_sys_execve+0x8a/0xb0 fs/exec.c:1959
do_syscall_64+0xa0/0x2e0 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 12577:
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0x129/0x170 mm/kasan/kasan.c:521
slab_free_hook mm/slub.c:1370 [inline]
slab_free_freelist_hook mm/slub.c:1397 [inline]
slab_free mm/slub.c:2952 [inline]
kfree+0x8b/0x1a0 mm/slub.c:3904
load_elf_binary+0x1be7/0x4610 fs/binfmt_elf.c:1118
search_binary_handler fs/exec.c:1654 [inline]
search_binary_handler+0x15c/0x4e0 fs/exec.c:1632
exec_binprm fs/exec.c:1696 [inline]
__do_execve_file.isra.0+0xf52/0x1a90 fs/exec.c:1820
do_execveat_common fs/exec.c:1866 [inline]
do_execve fs/exec.c:1883 [inline]
__do_sys_execve fs/exec.c:1964 [inline]
__se_sys_execve fs/exec.c:1959 [inline]
__x64_sys_execve+0x8a/0xb0 fs/exec.c:1959
do_syscall_64+0xa0/0x2e0 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88803b8ccf00
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 259 bytes inside of
512-byte region [ffff88803b8ccf00, ffff88803b8cd100)
The buggy address belongs to the page:
page:ffffea0000ee3300 count:1 mapcount:0 mapping:ffff88806cc03080
index:0xffff88803b8cc780 compound_mapcount: 0
flags: 0x100000000008100(slab|head)
raw: 0100000000008100 ffffea0001104080 0000000200000002 ffff88806cc03080
raw: ffff88803b8cc780 00000000800c000b 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88803b8ccf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88803b8ccf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
&gt;ffff88803b8cd000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88803b8cd080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88803b8cd100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

You can refer to "https://www.lkml.org/lkml/2019/1/17/474" reproduce
this error.

The exception code is "bd_len = p[3];", "p" value is ffff88803b8cd000
which belongs to the cache kmalloc-512 of size 512. The "page_address(sg_page(scsi_sglist(scmd)))"
maybe from sg_scsi_ioctl function "buffer" which allocated by kzalloc, so "buffer"
may not page aligned.
This also looks completely buggy on highmem systems and really needs to use a
kmap_atomic.      --Christoph Hellwig
To address above bugs, Paolo Bonzini advise to simpler to just make a char array
of size CACHE_MPAGE_LEN+8+8+4-2(or just 64 to make it easy), use sg_copy_to_buffer
to copy from the sglist into the buffer, and workthere.

Signed-off-by: Ye Bin &lt;yebin10@huawei.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>libata: Remove extra scsi_host_put() in ata_scsi_add_hosts()</title>
<updated>2020-04-24T05:58:48Z</updated>
<author>
<name>John Garry</name>
</author>
<published>2020-02-28T11:33:35Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=2e70b9a8adbdb7ec8d743f0a6abe77954eb1f71f'/>
<id>urn:sha1:2e70b9a8adbdb7ec8d743f0a6abe77954eb1f71f</id>
<content type='text'>
[ Upstream commit 1d72f7aec3595249dbb83291ccac041a2d676c57 ]

If the call to scsi_add_host_with_dma() in ata_scsi_add_hosts() fails,
then we may get use-after-free KASAN warns:

==================================================================
BUG: KASAN: use-after-free in kobject_put+0x24/0x180
Read of size 1 at addr ffff0026b8c80364 by task swapper/0/1
CPU: 1 PID: 1 Comm: swapper/0 Tainted: G        W         5.6.0-rc3-00004-g5a71b206ea82-dirty #1765
Hardware name: Huawei TaiShan 200 (Model 2280)/BC82AMDD, BIOS 2280-V2 CS V3.B160.01 02/24/2020
Call trace:
dump_backtrace+0x0/0x298
show_stack+0x14/0x20
dump_stack+0x118/0x190
print_address_description.isra.9+0x6c/0x3b8
__kasan_report+0x134/0x23c
kasan_report+0xc/0x18
__asan_load1+0x5c/0x68
kobject_put+0x24/0x180
put_device+0x10/0x20
scsi_host_put+0x10/0x18
ata_devres_release+0x74/0xb0
release_nodes+0x2d0/0x470
devres_release_all+0x50/0x78
really_probe+0x2d4/0x560
driver_probe_device+0x7c/0x148
device_driver_attach+0x94/0xa0
__driver_attach+0xa8/0x110
bus_for_each_dev+0xe8/0x158
driver_attach+0x30/0x40
bus_add_driver+0x220/0x2e0
driver_register+0xbc/0x1d0
__pci_register_driver+0xbc/0xd0
ahci_pci_driver_init+0x20/0x28
do_one_initcall+0xf0/0x608
kernel_init_freeable+0x31c/0x384
kernel_init+0x10/0x118
ret_from_fork+0x10/0x18

Allocated by task 5:
save_stack+0x28/0xc8
__kasan_kmalloc.isra.8+0xbc/0xd8
kasan_kmalloc+0xc/0x18
__kmalloc+0x1a8/0x280
scsi_host_alloc+0x44/0x678
ata_scsi_add_hosts+0x74/0x268
ata_host_register+0x228/0x488
ahci_host_activate+0x1c4/0x2a8
ahci_init_one+0xd18/0x1298
local_pci_probe+0x74/0xf0
work_for_cpu_fn+0x2c/0x48
process_one_work+0x488/0xc08
worker_thread+0x330/0x5d0
kthread+0x1c8/0x1d0
ret_from_fork+0x10/0x18

Freed by task 5:
save_stack+0x28/0xc8
__kasan_slab_free+0x118/0x180
kasan_slab_free+0x10/0x18
slab_free_freelist_hook+0xa4/0x1a0
kfree+0xd4/0x3a0
scsi_host_dev_release+0x100/0x148
device_release+0x7c/0xe0
kobject_put+0xb0/0x180
put_device+0x10/0x20
scsi_host_put+0x10/0x18
ata_scsi_add_hosts+0x210/0x268
ata_host_register+0x228/0x488
ahci_host_activate+0x1c4/0x2a8
ahci_init_one+0xd18/0x1298
local_pci_probe+0x74/0xf0
work_for_cpu_fn+0x2c/0x48
process_one_work+0x488/0xc08
worker_thread+0x330/0x5d0
kthread+0x1c8/0x1d0
ret_from_fork+0x10/0x18

There is also refcount issue, as well:
WARNING: CPU: 1 PID: 1 at lib/refcount.c:28 refcount_warn_saturate+0xf8/0x170

The issue is that we make an erroneous extra call to scsi_host_put()
for that host:

So in ahci_init_one()-&gt;ata_host_alloc_pinfo()-&gt;ata_host_alloc(), we setup
a device release method - ata_devres_release() - which intends to release
the SCSI hosts:

static void ata_devres_release(struct device *gendev, void *res)
{
	...
	for (i = 0; i &lt; host-&gt;n_ports; i++) {
		struct ata_port *ap = host-&gt;ports[i];

		if (!ap)
			continue;

		if (ap-&gt;scsi_host)
			scsi_host_put(ap-&gt;scsi_host);

	}
	...
}

However in the ata_scsi_add_hosts() error path, we also call
scsi_host_put() for the SCSI hosts.

Fix by removing the the scsi_host_put() calls in ata_scsi_add_hosts() and
leave this to ata_devres_release().

Fixes: f31871951b38 ("libata: separate out ata_host_alloc() and ata_host_register()")
Signed-off-by: John Garry &lt;john.garry@huawei.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>libata: have ata_scsi_rw_xlat() fail invalid passthrough requests</title>
<updated>2019-11-25T08:53:15Z</updated>
<author>
<name>Jens Axboe</name>
</author>
<published>2019-08-07T18:20:52Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=31941e54e35295e66fa1a6e749f5faf0332bc7f5'/>
<id>urn:sha1:31941e54e35295e66fa1a6e749f5faf0332bc7f5</id>
<content type='text'>
commit 2d7271501720038381d45fb3dcbe4831228fc8cc upstream.

For passthrough requests, libata-scsi takes what the user passes in
as gospel. This can be problematic if the user fills in the CDB
incorrectly. One example of that is in request sizes. For read/write
commands, the CDB contains fields describing the transfer length of
the request. These should match with the SG_IO header fields, but
libata-scsi currently does no validation of that.

Check that the number of blocks in the CDB for passthrough requests
matches what was mapped into the request. If the CDB asks for more
data then the validated SG_IO header fields, error it.

Reported-by: Krishna Ram Prakash R &lt;krp@gtux.in&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>ata: Fix ZBC_OUT all bit handling</title>
<updated>2018-07-17T09:37:51Z</updated>
<author>
<name>Damien Le Moal</name>
</author>
<published>2018-06-26T11:56:55Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=3f205d7a89d96d50fcf9a44754c180908388da25'/>
<id>urn:sha1:3f205d7a89d96d50fcf9a44754c180908388da25</id>
<content type='text'>
commit 6edf1d4cb0acde3a0a5dac849f33031bd7abb7b1 upstream.

If the ALL bit is set in the ZBC_OUT command, the command zone ID field
(block) should be ignored.

Reported-by: David Butterfield &lt;david.butterfield@wdc.com&gt;
Signed-off-by: Damien Le Moal &lt;damien.lemoal@wdc.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>ata: Fix ZBC_OUT command block check</title>
<updated>2018-07-17T09:37:51Z</updated>
<author>
<name>Damien Le Moal</name>
</author>
<published>2018-06-26T11:56:54Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=51bacd848cc1bcd8fb82d413cf27f407973536f5'/>
<id>urn:sha1:51bacd848cc1bcd8fb82d413cf27f407973536f5</id>
<content type='text'>
commit b320a0a9f23c98f21631eb27bcbbca91c79b1c6e upstream.

The block (LBA) specified must not exceed the last addressable LBA,
which is dev-&gt;nr_sectors - 1. So fix the correct check is
"if (block &gt;= dev-&gt;n_sectors)" and not "if (block &gt; dev-&gt;n_sectords)".

Additionally, the asc/ascq to return for an LBA that is not a zone start
LBA should be ILLEGAL REQUEST, regardless if the bad LBA is out of
range.

Reported-by: David Butterfield &lt;david.butterfield@wdc.com&gt;
Signed-off-by: Damien Le Moal &lt;damien.lemoal@wdc.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>libata: Fix compile warning with ATA_DEBUG enabled</title>
<updated>2018-05-30T05:50:27Z</updated>
<author>
<name>Dong Bo</name>
</author>
<published>2018-01-26T03:21:49Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=3a6ebe27cc8bc541bd27c710ea11d36771234091'/>
<id>urn:sha1:3a6ebe27cc8bc541bd27c710ea11d36771234091</id>
<content type='text'>
[ Upstream commit 0d3e45bc6507bd1f8728bf586ebd16c2d9e40613 ]

This fixs the following comile warnings with ATA_DEBUG enabled,
which detected by Linaro GCC 5.2-2015.11:

  drivers/ata/libata-scsi.c: In function 'ata_scsi_dump_cdb':
  ./include/linux/kern_levels.h:5:18: warning: format '%d' expects
  argument of type 'int', but argument 6 has type 'u64 {aka long
   long unsigned int}' [-Wformat=]

tj: Patch hand-applied and description trimmed.

Signed-off-by: Dong Bo &lt;dongbo4@huawei.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>libata: don't try to pass through NCQ commands to non-NCQ devices</title>
<updated>2018-03-28T16:39:20Z</updated>
<author>
<name>Eric Biggers</name>
</author>
<published>2018-02-04T04:33:51Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=8b8524d75697da34116c3fd42103b67f69f3dcc8'/>
<id>urn:sha1:8b8524d75697da34116c3fd42103b67f69f3dcc8</id>
<content type='text'>
commit 2c1ec6fda2d07044cda922ee25337cf5d4b429b3 upstream.

syzkaller hit a WARN() in ata_bmdma_qc_issue() when writing to /dev/sg0.
This happened because it issued an ATA pass-through command (ATA_16)
where the protocol field indicated that NCQ should be used -- but the
device did not support NCQ.

We could just remove the WARN() from libata-sff.c, but the real problem
seems to be that the SCSI -&gt; ATA translation code passes through NCQ
commands without verifying that the device actually supports NCQ.

Fix this by adding the appropriate check to ata_scsi_pass_thru().

Here's reproducer that works in QEMU when /dev/sg0 refers to a disk of
the default type ("82371SB PIIX3 IDE"):

    #include &lt;fcntl.h&gt;
    #include &lt;unistd.h&gt;

    int main()
    {
            char buf[53] = { 0 };

	    buf[36] = 0x85;		/* ATA_16 */
	    buf[37] = (12 &lt;&lt; 1);	/* FPDMA */
	    buf[38] = 0x1;		/* Has data */
	    buf[51] = 0xC8;		/* ATA_CMD_READ */
            write(open("/dev/sg0", O_RDWR), buf, sizeof(buf));
    }

Fixes: ee7fb331c3ac ("libata: add support for NCQ commands for SG interface")
Reported-by: syzbot+2f69ca28df61bdfc77cd36af2e789850355a221e@syzkaller.appspotmail.com
Cc: &lt;stable@vger.kernel.org&gt; # v4.4+
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>libata: fix length validation of ATAPI-relayed SCSI commands</title>
<updated>2018-03-28T16:39:20Z</updated>
<author>
<name>Eric Biggers</name>
</author>
<published>2018-02-04T04:30:56Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=85f0fec12c58509b0e3717ad07427aa508a2d869'/>
<id>urn:sha1:85f0fec12c58509b0e3717ad07427aa508a2d869</id>
<content type='text'>
commit 058f58e235cbe03e923b30ea7c49995a46a8725f upstream.

syzkaller reported a crash in ata_bmdma_fill_sg() when writing to
/dev/sg1.  The immediate cause was that the ATA command's scatterlist
was not DMA-mapped, which causes 'pi - 1' to underflow, resulting in a
write to 'qc-&gt;ap-&gt;bmdma_prd[0xffffffff]'.

Strangely though, the flag ATA_QCFLAG_DMAMAP was set in qc-&gt;flags.  The
root cause is that when __ata_scsi_queuecmd() is preparing to relay a
SCSI command to an ATAPI device, it doesn't correctly validate the CDB
length before copying it into the 16-byte buffer 'cdb' in 'struct
ata_queued_cmd'.  Namely, it validates the fixed CDB length expected
based on the SCSI opcode but not the actual CDB length, which can be
larger due to the use of the SG_NEXT_CMD_LEN ioctl.  Since 'flags' is
the next member in ata_queued_cmd, a buffer overflow corrupts it.

Fix it by requiring that the actual CDB length be &lt;= 16 (ATAPI_CDB_LEN).

[Really it seems the length should be required to be &lt;= dev-&gt;cdb_len,
but the current behavior seems to have been intentionally introduced by
commit 607126c2a21c ("libata-scsi: be tolerant of 12-byte ATAPI commands
in 16-byte CDBs") to work around a userspace bug in mplayer.  Probably
the workaround is no longer needed (mplayer was fixed in 2007), but
continuing to allow lengths to up 16 appears harmless for now.]

Here's a reproducer that works in QEMU when /dev/sg1 refers to the
CD-ROM drive that qemu-system-x86_64 creates by default:

    #include &lt;fcntl.h&gt;
    #include &lt;sys/ioctl.h&gt;
    #include &lt;unistd.h&gt;

    #define SG_NEXT_CMD_LEN 0x2283

    int main()
    {
	    char buf[53] = { [36] = 0x7e, [52] = 0x02 };
	    int fd = open("/dev/sg1", O_RDWR);
	    ioctl(fd, SG_NEXT_CMD_LEN, &amp;(int){ 17 });
	    write(fd, buf, sizeof(buf));
    }

The crash was:

    BUG: unable to handle kernel paging request at ffff8cb97db37ffc
    IP: ata_bmdma_fill_sg drivers/ata/libata-sff.c:2623 [inline]
    IP: ata_bmdma_qc_prep+0xa4/0xc0 drivers/ata/libata-sff.c:2727
    PGD fb6c067 P4D fb6c067 PUD 0
    Oops: 0002 [#1] SMP
    CPU: 1 PID: 150 Comm: syz_ata_bmdma_q Not tainted 4.15.0-next-20180202 #99
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014
    [...]
    Call Trace:
     ata_qc_issue+0x100/0x1d0 drivers/ata/libata-core.c:5421
     ata_scsi_translate+0xc9/0x1a0 drivers/ata/libata-scsi.c:2024
     __ata_scsi_queuecmd drivers/ata/libata-scsi.c:4326 [inline]
     ata_scsi_queuecmd+0x8c/0x210 drivers/ata/libata-scsi.c:4375
     scsi_dispatch_cmd+0xa2/0xe0 drivers/scsi/scsi_lib.c:1727
     scsi_request_fn+0x24c/0x530 drivers/scsi/scsi_lib.c:1865
     __blk_run_queue_uncond block/blk-core.c:412 [inline]
     __blk_run_queue+0x3a/0x60 block/blk-core.c:432
     blk_execute_rq_nowait+0x93/0xc0 block/blk-exec.c:78
     sg_common_write.isra.7+0x272/0x5a0 drivers/scsi/sg.c:806
     sg_write+0x1ef/0x340 drivers/scsi/sg.c:677
     __vfs_write+0x31/0x160 fs/read_write.c:480
     vfs_write+0xa7/0x160 fs/read_write.c:544
     SYSC_write fs/read_write.c:589 [inline]
     SyS_write+0x4d/0xc0 fs/read_write.c:581
     do_syscall_64+0x5e/0x110 arch/x86/entry/common.c:287
     entry_SYSCALL_64_after_hwframe+0x21/0x86

Fixes: 607126c2a21c ("libata-scsi: be tolerant of 12-byte ATAPI commands in 16-byte CDBs")
Reported-by: syzbot+1ff6f9fcc3c35f1c72a95e26528c8e7e3276e4da@syzkaller.appspotmail.com
Cc: &lt;stable@vger.kernel.org&gt; # v2.6.24+
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>libata: array underflow in ata_find_dev()</title>
<updated>2017-08-11T15:49:28Z</updated>
<author>
<name>Dan Carpenter</name>
</author>
<published>2017-07-19T10:06:41Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=804b1a9f0aeabc002b162c5b1861d65e1316a53a'/>
<id>urn:sha1:804b1a9f0aeabc002b162c5b1861d65e1316a53a</id>
<content type='text'>
commit 59a5e266c3f5c1567508888dd61a45b86daed0fa upstream.

My static checker complains that "devno" can be negative, meaning that
we read before the start of the loop.  I've looked at the code, and I
think the warning is right.  This come from /proc so it's root only or
it would be quite a quite a serious bug.  The call tree looks like this:

proc_scsi_write() &lt;- gets id and channel from simple_strtoul()
-&gt; scsi_add_single_device() &lt;- calls shost-&gt;transportt-&gt;user_scan()
   -&gt; ata_scsi_user_scan()
      -&gt; ata_find_dev()

Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
</feed>
