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SubjectRe: [PATCH 0/3] scsi: qedf: sanitise uaccess
Date
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[unhandled content-type:application/pgp-signature]
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