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| author | Yunjian Wang <[email protected]> | 2021-06-04 11:03:18 +0000 |
|---|---|---|
| committer | David S. Miller <[email protected]> | 2021-06-04 21:44:18 +0000 |
| commit | 944d671d5faa0d78980a3da5c0f04960ef1ad893 (patch) | |
| tree | 61215bceb853496d1e709ad7a4ad2658878d51f6 /tools/perf/scripts/python/flamegraph.py | |
| parent | Merge branch '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/... (diff) | |
| download | kernel-944d671d5faa0d78980a3da5c0f04960ef1ad893.tar.gz kernel-944d671d5faa0d78980a3da5c0f04960ef1ad893.zip | |
sch_htb: fix refcount leak in htb_parent_to_leaf_offload
The commit ae81feb7338c ("sch_htb: fix null pointer dereference
on a null new_q") fixes a NULL pointer dereference bug, but it
is not correct.
Because htb_graft_helper properly handles the case when new_q
is NULL, and after the previous patch by skipping this call
which creates an inconsistency : dev_queue->qdisc will still
point to the old qdisc, but cl->parent->leaf.q will point to
the new one (which will be noop_qdisc, because new_q was NULL).
The code is based on an assumption that these two pointers are
the same, so it can lead to refcount leaks.
The correct fix is to add a NULL pointer check to protect
qdisc_refcount_inc inside htb_parent_to_leaf_offload.
Fixes: ae81feb7338c ("sch_htb: fix null pointer dereference on a null new_q")
Signed-off-by: Yunjian Wang <[email protected]>
Suggested-by: Maxim Mikityanskiy <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Diffstat (limited to 'tools/perf/scripts/python/flamegraph.py')
0 files changed, 0 insertions, 0 deletions