dm-devel.redhat.com archive mirror
 help / color / mirror / Atom feed
From: Mikulas Patocka <mpatocka@redhat.com>
To: Mike Snitzer <msnitzer@redhat.com>
Cc: dm-devel@redhat.com
Subject: [dm-devel] [PATCH] dm-integrity: fix double free on memory allocation failure
Date: Mon, 3 Jul 2023 17:12:39 +0200 (CEST)	[thread overview]
Message-ID: <372fae19-65df-9ba7-8df7-c8b9a43358cf@redhat.com> (raw)

Hi

I found a bug in one of the patches that I submitted. Here I'm submitting 
the fix. Please send it to Linus before 6.5 is released.

Mikulas


From: Mikulas Patocka <mpatocka@redhat.com>

If the statement "recalc_tags = kvmalloc(recalc_tags_size, GFP_NOIO);"
fails, we call "vfree(recalc_buffer)" and we jump to the label "oom".

If the condition "recalc_sectors >= 1U << ic->sb->log2_sectors_per_block"
is false, we jump to the label "free_ret" and call "vfree(recalc_buffer)"
again, on an already released memory block.

This commit fixes the bug by setting "recalc_buffer = NULL" after freeing
it.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: da8b4fc1f63a ("dm integrity: only allocate recalculate buffer when needed")

---
 drivers/md/dm-integrity.c |    1 +
 1 file changed, 1 insertion(+)

Index: linux-2.6/drivers/md/dm-integrity.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-integrity.c
+++ linux-2.6/drivers/md/dm-integrity.c
@@ -2691,6 +2691,7 @@ oom:
 	recalc_tags = kvmalloc(recalc_tags_size, GFP_NOIO);
 	if (!recalc_tags) {
 		vfree(recalc_buffer);
+		recalc_buffer = NULL;
 		goto oom;
 	}
 
--
dm-devel mailing list
dm-devel@redhat.com
https://listman.redhat.com/mailman/listinfo/dm-devel


                 reply	other threads:[~2023-07-03 15:13 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=372fae19-65df-9ba7-8df7-c8b9a43358cf@redhat.com \
    --to=mpatocka@redhat.com \
    --cc=dm-devel@redhat.com \
    --cc=msnitzer@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).