diff mbox series

[net-next] bpf: avoid the multi checking

Message ID 20221121100521.56601-1-xiangxia.m.yue@gmail.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series [net-next] bpf: avoid the multi checking | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 12 this patch: 12
netdev/cc_maintainers warning 1 maintainers not CCed: bpf@vger.kernel.org
netdev/build_clang success Errors and warnings before: 5 this patch: 5
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 12 this patch: 12
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 13 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-PR fail PR summary
bpf/vmtest-bpf-next-VM_Test-11 success Logs for test_maps on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-1 success Logs for ShellCheck
bpf/vmtest-bpf-next-VM_Test-7 success Logs for llvm-toolchain
bpf/vmtest-bpf-next-VM_Test-8 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-2 success Logs for build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-3 success Logs for build for aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-5 success Logs for build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-6 success Logs for build for x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-4 success Logs for build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-12 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-28 success Logs for test_progs_no_alu32_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-37 success Logs for test_verifier on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-38 success Logs for test_verifier on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-9 success Logs for test_maps on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-10 success Logs for test_maps on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-13 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-14 fail Logs for test_progs on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-17 fail Logs for test_progs on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-18 fail Logs for test_progs on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-19 fail Logs for test_progs_no_alu32 on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-20 fail Logs for test_progs_no_alu32 on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-22 fail Logs for test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-23 fail Logs for test_progs_no_alu32 on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-24 success Logs for test_progs_no_alu32_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-27 success Logs for test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-29 success Logs for test_progs_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-32 success Logs for test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-33 success Logs for test_progs_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-34 success Logs for test_verifier on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-35 success Logs for test_verifier on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-15 fail Logs for test_progs on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-25 success Logs for test_progs_no_alu32_parallel on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-30 success Logs for test_progs_parallel on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-26 success Logs for test_progs_no_alu32_parallel on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-16 fail Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-21 fail Logs for test_progs_no_alu32 on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-31 success Logs for test_progs_parallel on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-36 success Logs for test_verifier on s390x with gcc

Commit Message

Tonghao Zhang Nov. 21, 2022, 10:05 a.m. UTC 
From: Tonghao Zhang <xiangxia.m.yue@gmail.com>

.map_alloc_check checked bpf_attr::max_entries, and if bpf_attr::max_entries
== 0, return -EINVAL. bpf_htab::n_buckets will not be 0, while -E2BIG is not
appropriate.

Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Song Liu <song@kernel.org>
Cc: Yonghong Song <yhs@fb.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
---
 kernel/bpf/hashtab.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Comments

Daniel Borkmann Nov. 22, 2022, 10:16 p.m. UTC | #1 
On 11/21/22 11:05 AM, xiangxia.m.yue@gmail.com wrote:
> From: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> 
> .map_alloc_check checked bpf_attr::max_entries, and if bpf_attr::max_entries
> == 0, return -EINVAL. bpf_htab::n_buckets will not be 0, while -E2BIG is not
> appropriate.
> 
> Cc: Alexei Starovoitov <ast@kernel.org>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Andrii Nakryiko <andrii@kernel.org>
> Cc: Martin KaFai Lau <martin.lau@linux.dev>
> Cc: Song Liu <song@kernel.org>
> Cc: Yonghong Song <yhs@fb.com>
> Cc: John Fastabend <john.fastabend@gmail.com>
> Cc: KP Singh <kpsingh@kernel.org>
> Cc: Stanislav Fomichev <sdf@google.com>
> Cc: Hao Luo <haoluo@google.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>

Pls Cc bpf@vger.kernel.org list and $subj line should target bpf-next.

> ---
>   kernel/bpf/hashtab.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
> index 50d254cd0709..22855d6ff6d3 100644
> --- a/kernel/bpf/hashtab.c
> +++ b/kernel/bpf/hashtab.c
> @@ -500,9 +500,10 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
>   		htab->elem_size += round_up(htab->map.value_size, 8);
>   
>   	err = -E2BIG;
> -	/* prevent zero size kmalloc and check for u32 overflow */
> -	if (htab->n_buckets == 0 ||
> -	    htab->n_buckets > U32_MAX / sizeof(struct bucket))
> +	/* avoid zero size and u32 overflow kmalloc.
> +	 * bpf_attr::max_entries checked in .map_alloc_check().
> +	 */
> +	if (htab->n_buckets > U32_MAX / sizeof(struct bucket))

This looks buggy to remove it, this is to guard against the previous
roundup_pow_of_two() on htab->n_buckets.

>   		goto free_htab;
>   
>   	err = -ENOMEM;
>
diff mbox series

Patch

diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 50d254cd0709..22855d6ff6d3 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -500,9 +500,10 @@  static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 		htab->elem_size += round_up(htab->map.value_size, 8);
 
 	err = -E2BIG;
-	/* prevent zero size kmalloc and check for u32 overflow */
-	if (htab->n_buckets == 0 ||
-	    htab->n_buckets > U32_MAX / sizeof(struct bucket))
+	/* avoid zero size and u32 overflow kmalloc.
+	 * bpf_attr::max_entries checked in .map_alloc_check().
+	 */
+	if (htab->n_buckets > U32_MAX / sizeof(struct bucket))
 		goto free_htab;
 
 	err = -ENOMEM;