Re: [PATCH] block, bfq: fix uaf for bfqq in bic_set_bfqq()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]



在 2023/02/21 18:19, Holger Hoffstätte 写道:
On 2023-02-21 08:04, Yu Kuai wrote:
Hi, Jens

在 2023/01/13 17:44, Yu Kuai 写道:
After commit 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'"),
bic->bfqq will be accessed in bic_set_bfqq(), however, in some context
bic->bfqq will be freed first, and bic_set_bfqq() is called with the freed

Fix the problem by always freeing bfqq after bic_set_bfqq().

Fixes: 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'")
Reported-and-tested-by: Shinichiro Kawasaki <shinichiro.kawasaki@xxxxxxx>
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
  block/bfq-cgroup.c  | 2 +-
  block/bfq-iosched.c | 4 +++-
  2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index a6e8da5f5cfd..feb13ac25557 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -749,8 +749,8 @@ static void bfq_sync_bfqq_move(struct bfq_data *bfqd,
           * old cgroup.
-        bfq_release_process_ref(bfqd, sync_bfqq);
          bic_set_bfqq(bic, NULL, true, act_idx);
+        bfq_release_process_ref(bfqd, sync_bfqq);

It seems this change is missed in GIT PULL for-6.3. I'll send a seperate
patch to fix this...

It was already applied in time for 6.2 as b600de2d7d3a16f9007fad1bdae82a3951a26af2
and also already merged to 6.1-stable.

Yes, 6.2 and 6.1 doesn't have such problem because bfq_sync_bfqq_move()
doesn't exist. The problem only exist in master branch currently.




[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]     [Monitors]

  Powered by Linux