Re: [PATCH v1 1/1] test_firmware: prevent race conditions by a correct implementation of locking

[Mirsad Todorovac]

On 8/1/23 10:24, Mirsad Todorovac wrote:
> On 7/31/23 19:27, Luis Chamberlain wrote:
> > On Mon, Jul 31, 2023 at 06:50:19PM +0200, Mirsad Todorovac wrote:
> > > NOTE: This patch is tested against 5.4 stable
> > >
> > > NOTE: This is a patch for the 5.4 stable branch, not for the torvalds tree.
> > >
> > >        The torvalds tree, and stable tree 5.10, 5.15, 6.1 and 6.4 branches
> > >        were fixed in the separate
> > >        commit ID 4acfe3dfde68 ("test_firmware: prevent race conditions by a correct implementation of locking")
> > >        which was incompatible with 5.4
> >
> > The above part is not part of the original commit, you also forgot to
> > mention the upstream commit:
> >
> > [ Upstream commit 4acfe3dfde685a5a9eaec5555351918e2d7266a1 ]
>
> Will fix. Actually, I wasn't sure if it was required, because this backported patch
> isn't verbatim equal to commit 4acfe3dfde685a5a9eaec5555351918e2d7266a1 .
>
> Though they are cousins, addressing the same issue.
>
> There is a race to be fixed, despite not all racy functions present in the original commit c92316bf8e948.
>
> > > Fixes: c92316bf8e948 ("test_firmware: add batched firmware tests")
> > > Cc: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
> > > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > > Cc: Russ Weight <russell.h.weight@xxxxxxxxx>
> > > Cc: Takashi Iwai <tiwai@xxxxxxx>
> > > Cc: Tianfei Zhang <tianfei.zhang@xxxxxxxxx>
> > > Cc: Shuah Khan <shuah@xxxxxxxxxx>
> > > Cc: Colin Ian King <colin.i.king@xxxxxxxxx>
> > > Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> > > Cc: linux-kselftest@xxxxxxxxxxxxxxx
> > > Cc: stable@xxxxxxxxxxxxxxx # v5.4
> > > Suggested-by: Dan Carpenter <error27@xxxxxxxxx>
> >
> > Here you can add the above note in brackets:
> >
> > [ explain your changes here from the original commit ]
> >
> > Then, I see two commits upstream on Linus tree which are also fixes
> > but not merged on v5.4, did you want those applied too?
>
> These seem merged in the stable 5.4?
>
> commit 75d9e00f65cd2e0f2ce9ceeb395f821976773489 test_firmware: fix a memory leak with reqs buffer
> commit 94f3bc7e84af2f17dbfbc7afe93991c2a6f2f25e test_firmware: fix the memory leak of the allocated firmware buffer
>
> Maybe this commit should be backported instead:
>
> test_firmware: return ENOMEM instead of ENOSPC on failed memory allocation
> [ Upstream commit 7dae593cd226a0bca61201cf85ceb9335cf63682 ]
>
> It was also merged into 6.4, 6.1, 5.15 and 5.10 stable, but not on 5.4
>
> I might also check whether the 4.19 and 4.14 are vulnerable to these memory leaks and this race
> (Yes, they are, so it might be prudent that we backport this fix.)

FYI, just checked, the patch applied w/o modifications to 4.19 and 4.14 LTS stable branches.

Mirsad

--
Mirsad Todorovac
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu

System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb, Republic of Croatia