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bpf: Check for integer overflow when using roundup_pow_of_two()

Message ID 20210127063653.3576-1-minhquangbui99@gmail.com (mailing list archive)
State Accepted
Commit 6183f4d3a0a2ad230511987c6c362ca43ec0055f
Delegated to: BPF
Headers show
Series bpf: Check for integer overflow when using roundup_pow_of_two() | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Bui Quang Minh Jan. 27, 2021, 6:36 a.m. UTC
On 32-bit architecture, roundup_pow_of_two() can return 0 when the argument
has upper most bit set due to resulting 1UL << 32. Add a check for this
case.

Fixes: d5a3b1f ("bpf: introduce BPF_MAP_TYPE_STACK_TRACE")
Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
---
 kernel/bpf/stackmap.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

patchwork-bot+netdevbpf@kernel.org Feb. 3, 2021, 8:50 p.m. UTC | #1
Hello:

This patch was applied to bpf/bpf.git (refs/heads/master):

On Wed, 27 Jan 2021 06:36:53 +0000 you wrote:
> On 32-bit architecture, roundup_pow_of_two() can return 0 when the argument
> has upper most bit set due to resulting 1UL << 32. Add a check for this
> case.
> 
> Fixes: d5a3b1f ("bpf: introduce BPF_MAP_TYPE_STACK_TRACE")
> Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
> 
> [...]

Here is the summary with links:
  - bpf: Check for integer overflow when using roundup_pow_of_two()
    https://git.kernel.org/bpf/bpf/c/6183f4d3a0a2

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index aea96b638473..bfafbf115bf3 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -115,6 +115,8 @@  static struct bpf_map *stack_map_alloc(union bpf_attr *attr)
 
 	/* hash table size must be power of 2 */
 	n_buckets = roundup_pow_of_two(attr->max_entries);
+	if (!n_buckets)
+		return ERR_PTR(-E2BIG);
 
 	cost = n_buckets * sizeof(struct stack_map_bucket *) + sizeof(*smap);
 	cost += n_buckets * (value_size + sizeof(struct stack_map_bucket));