The following commit has been merged into the perf/core branch of tip: Commit-ID: dbc48c8f41c208082cfa95e973560134489e3309 Gitweb: https://git.kernel.org/tip/dbc48c8f41c208082cfa95e973560134489e3309 Author: Adrian Hunter <adrian.hunter@xxxxxxxxx> AuthorDate: Mon, 24 Jun 2024 23:10:59 +03:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Thu, 04 Jul 2024 16:00:22 +02:00 perf: Prevent passing zero nr_pages to rb_alloc_aux() nr_pages is unsigned long but gets passed to rb_alloc_aux() as an int, and is stored as an int. Only power-of-2 values are accepted, so if nr_pages is a 64_bit value, it will be passed to rb_alloc_aux() as zero. That is not ideal because: 1. the value is incorrect 2. rb_alloc_aux() is at risk of misbehaving, although it manages to return -ENOMEM in that case, it is a result of passing zero to get_order() even though the get_order() result is documented to be undefined in that case. Fix by simply validating the maximum supported value in the first place. Use -ENOMEM error code for consistency with the current error code that is returned in that case. Fixes: 45bfb2e50471 ("perf: Add AUX area to ring buffer for raw data streams") Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20240624201101.60186-6-adrian.hunter@xxxxxxxxx --- kernel/events/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index 6b0a66e..e70d3dd 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6496,6 +6496,8 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) return -EINVAL; nr_pages = vma_size / PAGE_SIZE; + if (nr_pages > INT_MAX) + return -ENOMEM; mutex_lock(&event->mmap_mutex); ret = -EINVAL;
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