diff options
| author | Eli Cohen <elic@nvidia.com> | 2023-02-08 07:51:02 +0200 |
|---|---|---|
| committer | Saeed Mahameed <saeedm@nvidia.com> | 2023-03-24 16:03:52 -0700 |
| commit | 4e0473f1060aa49621d40a113afde24818101d37 (patch) | |
| tree | 2db1638290f344047b2651332f4919ede909513a | |
| parent | e8d018dd0257f744ca50a729e3d042cf2ec9da65 (diff) | |
lib: cpu_rmap: Avoid use after free on rmap->obj array entries
When calling irq_set_affinity_notifier() with NULL at the notify
argument, it will cause freeing of the glue pointer in the
corresponding array entry but will leave the pointer in the array. A
subsequent call to free_irq_cpu_rmap() will try to free this entry again
leading to possible use after free.
Fix that by setting NULL to the array entry and checking that we have
non-zero at the array entry when iterating over the array in
free_irq_cpu_rmap().
The current code does not suffer from this since there are no cases
where irq_set_affinity_notifier(irq, NULL) (note the NULL passed for the
notify arg) is called, followed by a call to free_irq_cpu_rmap() so we
don't hit and issue. Subsequent patches in this series excersize this
flow, hence the required fix.
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Eli Cohen <elic@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
| -rw-r--r-- | lib/cpu_rmap.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/lib/cpu_rmap.c b/lib/cpu_rmap.c index f08d9c56f712..e77f12bb3c77 100644 --- a/lib/cpu_rmap.c +++ b/lib/cpu_rmap.c @@ -232,7 +232,8 @@ void free_irq_cpu_rmap(struct cpu_rmap *rmap) for (index = 0; index < rmap->used; index++) { glue = rmap->obj[index]; - irq_set_affinity_notifier(glue->notify.irq, NULL); + if (glue) + irq_set_affinity_notifier(glue->notify.irq, NULL); } cpu_rmap_put(rmap); @@ -268,6 +269,7 @@ static void irq_cpu_rmap_release(struct kref *ref) container_of(ref, struct irq_glue, notify.kref); cpu_rmap_put(glue->rmap); + glue->rmap->obj[glue->index] = NULL; kfree(glue); } @@ -297,6 +299,7 @@ int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq) rc = irq_set_affinity_notifier(irq, &glue->notify); if (rc) { cpu_rmap_put(glue->rmap); + rmap->obj[glue->index] = NULL; kfree(glue); } return rc; |