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

[Saurav Kashyap]

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

> -----Original Message-----
> From: Oleksandr Natalenko <oleksandr@xxxxxxxxxx>
> Sent: Friday, July 28, 2023 12:28 PM
> To: linux-kernel@xxxxxxxxxxxxxxx
> Cc: linux-scsi@xxxxxxxxxxxxxxx; Saurav Kashyap <skashyap@xxxxxxxxxxx>;
> Johannes Thumshirn <Johannes.Thumshirn@xxxxxxx>; GR-QLogic-Storage-
> Upstream <GR-QLogic-Storage-Upstream@xxxxxxxxxxx>; James E.J. Bottomley
> <jejb@xxxxxxxxxxxxx>; Martin K. Petersen <martin.petersen@xxxxxxxxxx>;
> Jozef Bacik <jobacik@xxxxxxxxxx>; Laurence Oberman
> <loberman@xxxxxxxxxx>; Rob Evers <revers@xxxxxxxxxx>
> 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