Re: [PATCH] scsi: libfc: Fix potential buffer overflow in fc_ct_ms_fill()

[Martin K. Petersen]

On Mon, 15 Sep 2025 11:37:57 -0700, Alok Tiwari wrote:

> The fc_ct_ms_fill() helper currently formats the OS name and version
> into entry->value using "%s v%s". Since init_utsname()->sysname and
> ->release are unbounded strings, snprintf() may attempt to write more
> than FC_FDMI_HBA_ATTR_OSNAMEVERSION_LEN bytes, triggering a
> -Wformat-truncation warning with W=1.
> 
> In file included from drivers/scsi/libfc/fc_elsct.c:18:
> drivers/scsi/libfc/fc_encode.h: In function ‘fc_ct_ms_fill.constprop’:
> drivers/scsi/libfc/fc_encode.h:359:30: error: ‘%s’ directive output may
> be truncated writing up to 64 bytes into a region of size between 62
> and 126 [-Werror=format-truncation=]
>   359 |                         "%s v%s",
>       |                              ^~
>   360 |                         init_utsname()->sysname,
>   361 |                         init_utsname()->release);
>       |                         ~~~~~~~~~~~~~~~~~~~~~~~
> drivers/scsi/libfc/fc_encode.h:357:17: note: ‘snprintf’ output between
> 3 and 131 bytes into a destination of size 128
>   357 |                 snprintf((char *)&entry->value,
>       |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   358 |                         FC_FDMI_HBA_ATTR_OSNAMEVERSION_LEN,
>       |                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   359 |                         "%s v%s",
>       |                         ~~~~~~~~~
>   360 |                         init_utsname()->sysname,
>       |                         ~~~~~~~~~~~~~~~~~~~~~~~~
>   361 |                         init_utsname()->release);
>       |                         ~~~~~~~~~~~~~~~~~~~~~~~~
> 
> [...]

Applied to 6.18/scsi-queue, thanks!

[1/1] scsi: libfc: Fix potential buffer overflow in fc_ct_ms_fill()
      https://git.kernel.org/mkp/scsi/c/072fdd4b0be9

-- 
Martin K. Petersen