[v1] scsi: qedf: sanitise uaccess

[PATCH 0/3] scsi: qedf: sanitise uaccess

Posted by Oleksandr Natalenko 2 years, 6 months ago

qedf driver, debugfs part of it specifically, touches __user pointers
directly for printing out info to userspace via sprintf(), which may
cause crash like this:

BUG: unable to handle kernel paging request at 00007ffd1d6b43a0
IP: [<ffffffffaa7a882a>] string.isra.7+0x6a/0xf0
Oops: 0003 [#1] SMP
Call Trace:
 [<ffffffffaa7a9f31>] vsnprintf+0x201/0x6a0
 [<ffffffffaa7aa556>] sprintf+0x56/0x80
 [<ffffffffc04227ed>] qedf_dbg_stop_io_on_error_cmd_read+0x6d/0x90 [qedf]
 [<ffffffffaa65bb2f>] vfs_read+0x9f/0x170
 [<ffffffffaa65cb82>] SyS_pread64+0x92/0xc0

Avoid this by preparing the info in a kernel buffer first, either
allocated on stack for small printouts, or via vmalloc() for big ones,
and then copying it to the userspace properly.

Previous submission is an RFC: [1]. There are no code changes since
then. The RFC prefix is dropped. The Tested-by tag from Laurence is
added.

There's similar submission from Saurav [2], but we agreed I could nack
it and proceed with my one.

[1] https://lore.kernel.org/linux-scsi/20230724120241.40495-1-oleksandr@redhat.com/
[2] https://lore.kernel.org/linux-scsi/20230726101236.11922-1-skashyap@marvell.com/

Oleksandr Natalenko (3):
  scsi: qedf: do not touch __user pointer in
    qedf_dbg_stop_io_on_error_cmd_read() directly
  scsi: qedf: do not touch __user pointer in qedf_dbg_debug_cmd_read()
    directly
  scsi: qedf: do not touch __user pointer in qedf_dbg_fp_int_cmd_read()
    directly

 drivers/scsi/qedf/qedf_dbg.h     |  2 ++
 drivers/scsi/qedf/qedf_debugfs.c | 35 +++++++++++++++++++-------------
 2 files changed, 23 insertions(+), 14 deletions(-)

-- 
2.41.0

Re: [PATCH 0/3] scsi: qedf: sanitise uaccess

Posted by Johannes Thumshirn 2 years, 6 months ago

Looks good,

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

RE: [EXT] [PATCH 0/3] scsi: qedf: sanitise uaccess

Posted by Saurav Kashyap 2 years, 6 months ago

Acked-by: Saurav Kashyap <skashyap@marvell.com> for full series.

> -----Original Message-----
> From: Oleksandr Natalenko <oleksandr@redhat.com>
> Sent: Friday, July 28, 2023 12:28 PM
> To: linux-kernel@vger.kernel.org
> Cc: linux-scsi@vger.kernel.org; Saurav Kashyap <skashyap@marvell.com>;
> Johannes Thumshirn <Johannes.Thumshirn@wdc.com>; GR-QLogic-Storage-
> Upstream <GR-QLogic-Storage-Upstream@marvell.com>; James E.J. Bottomley
> <jejb@linux.ibm.com>; Martin K. Petersen <martin.petersen@oracle.com>;
> Jozef Bacik <jobacik@redhat.com>; Laurence Oberman
> <loberman@redhat.com>; Rob Evers <revers@redhat.com>
> Subject: [EXT] [PATCH 0/3] scsi: qedf: sanitise uaccess
> 
> External Email
> 
> ----------------------------------------------------------------------
> qedf driver, debugfs part of it specifically, touches __user pointers
> directly for printing out info to userspace via sprintf(), which may
> cause crash like this:
> 
> BUG: unable to handle kernel paging request at 00007ffd1d6b43a0
> IP: [<ffffffffaa7a882a>] string.isra.7+0x6a/0xf0
> Oops: 0003 [#1] SMP
> Call Trace:
>  [<ffffffffaa7a9f31>] vsnprintf+0x201/0x6a0
>  [<ffffffffaa7aa556>] sprintf+0x56/0x80
>  [<ffffffffc04227ed>] qedf_dbg_stop_io_on_error_cmd_read+0x6d/0x90
> [qedf]
>  [<ffffffffaa65bb2f>] vfs_read+0x9f/0x170
>  [<ffffffffaa65cb82>] SyS_pread64+0x92/0xc0
> 
> Avoid this by preparing the info in a kernel buffer first, either
> allocated on stack for small printouts, or via vmalloc() for big ones,
> and then copying it to the userspace properly.
> 
> Previous submission is an RFC: [1]. There are no code changes since
> then. The RFC prefix is dropped. The Tested-by tag from Laurence is
> added.
> 
> There's similar submission from Saurav [2], but we agreed I could nack
> it and proceed with my one.
> 
> [1] https://urldefense.proofpoint.com/v2/url?u=https-
> 3A__lore.kernel.org_linux-2Dscsi_20230724120241.40495-2D1-2Doleksandr-
> 40redhat.com_&d=DwIDAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=ZHZbmY_LbM3
> DUZK_BDO1OITP3ot_Vkb_5w-
> gas5TBMQ&m=I6CdYJNbvw1q9OWTYmMTCWzCcXFG7MelqlMZ_DmhEMDeW
> ViVj2b3_EadDZUUdzNT&s=joHzWsadjq2HUMSxGvJZMkLQULriRotQk2RYPgDW
> pWc&e=
> [2] https://urldefense.proofpoint.com/v2/url?u=https-
> 3A__lore.kernel.org_linux-2Dscsi_20230726101236.11922-2D1-2Dskashyap-
> 40marvell.com_&d=DwIDAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=ZHZbmY_LbM
> 3DUZK_BDO1OITP3ot_Vkb_5w-
> gas5TBMQ&m=I6CdYJNbvw1q9OWTYmMTCWzCcXFG7MelqlMZ_DmhEMDeW
> ViVj2b3_EadDZUUdzNT&s=q2LVoTVsEfj1rCnih48VaDUxOCOobRLhIaTatga1qm
> Q&e=
> 
> Oleksandr Natalenko (3):
>   scsi: qedf: do not touch __user pointer in
>     qedf_dbg_stop_io_on_error_cmd_read() directly
>   scsi: qedf: do not touch __user pointer in qedf_dbg_debug_cmd_read()
>     directly
>   scsi: qedf: do not touch __user pointer in qedf_dbg_fp_int_cmd_read()
>     directly
> 
>  drivers/scsi/qedf/qedf_dbg.h     |  2 ++
>  drivers/scsi/qedf/qedf_debugfs.c | 35 +++++++++++++++++++-------------
>  2 files changed, 23 insertions(+), 14 deletions(-)
> 
> --
> 2.41.0

Re: [PATCH 0/3] scsi: qedf: sanitise uaccess

Posted by Oleksandr Natalenko 2 years, 6 months ago

On pátek 28. července 2023 8:58:16 CEST Oleksandr Natalenko wrote:
> qedf driver, debugfs part of it specifically, touches __user pointers
> directly for printing out info to userspace via sprintf(), which may
> cause crash like this:
> 
> BUG: unable to handle kernel paging request at 00007ffd1d6b43a0
> IP: [<ffffffffaa7a882a>] string.isra.7+0x6a/0xf0
> Oops: 0003 [#1] SMP
> Call Trace:
>  [<ffffffffaa7a9f31>] vsnprintf+0x201/0x6a0
>  [<ffffffffaa7aa556>] sprintf+0x56/0x80
>  [<ffffffffc04227ed>] qedf_dbg_stop_io_on_error_cmd_read+0x6d/0x90 [qedf]
>  [<ffffffffaa65bb2f>] vfs_read+0x9f/0x170
>  [<ffffffffaa65cb82>] SyS_pread64+0x92/0xc0
> 
> Avoid this by preparing the info in a kernel buffer first, either
> allocated on stack for small printouts, or via vmalloc() for big ones,
> and then copying it to the userspace properly.
> 
> Previous submission is an RFC: [1]. There are no code changes since
> then. The RFC prefix is dropped. The Tested-by tag from Laurence is
> added.
> 
> There's similar submission from Saurav [2], but we agreed I could nack
> it and proceed with my one.
> 
> [1] https://lore.kernel.org/linux-scsi/20230724120241.40495-1-oleksandr@redhat.com/
> [2] https://lore.kernel.org/linux-scsi/20230726101236.11922-1-skashyap@marvell.com/
> 
> Oleksandr Natalenko (3):
>   scsi: qedf: do not touch __user pointer in
>     qedf_dbg_stop_io_on_error_cmd_read() directly
>   scsi: qedf: do not touch __user pointer in qedf_dbg_debug_cmd_read()
>     directly
>   scsi: qedf: do not touch __user pointer in qedf_dbg_fp_int_cmd_read()
>     directly
> 
>  drivers/scsi/qedf/qedf_dbg.h     |  2 ++
>  drivers/scsi/qedf/qedf_debugfs.c | 35 +++++++++++++++++++-------------
>  2 files changed, 23 insertions(+), 14 deletions(-)
> 
> 

Oops, I forgot to add:

Reviewed-by: Laurence Oberman <loberman@redhat.com>

as per [1].

My ask to the maintainer to add it if the submission is accepted, or let me know if I should do a v2 instead.

[1] https://lore.kernel.org/linux-scsi/4f35b02968a18e636e1689c9d52729ef63a438f9.camel@redhat.com/

-- 
Oleksandr Natalenko (post-factum)
Principal Software Maintenance Engineer