diff mbox series

[bpf-next,v4,4/7] netfilter: disallow bpf hook attachment at same priority

Message ID 20230420124455.31099-5-fw@strlen.de (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpf: add netfilter program type | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-10 success Logs for test_maps on s390x with gcc
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 20 this patch: 20
netdev/cc_maintainers warning 7 maintainers not CCed: pabeni@redhat.com pablo@netfilter.org kuba@kernel.org edumazet@google.com kadlec@netfilter.org coreteam@netfilter.org davem@davemloft.net
netdev/build_clang success Errors and warnings before: 18 this patch: 18
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
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: 20 this patch: 20
netdev/checkpatch warning WARNING: line length of 81 exceeds 80 columns WARNING: line length of 83 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-VM_Test-36 success Logs for veristat
bpf/vmtest-bpf-next-VM_Test-33 success Logs for test_verifier on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-20 fail Logs for test_progs_no_alu32 on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-15 fail Logs for test_progs 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 set-matrix
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-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-4 success Logs for build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-8 success Logs for test_maps on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-11 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-12 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-13 fail Logs for test_progs on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-16 fail Logs for test_progs on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-17 fail Logs for test_progs on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-18 fail Logs for test_progs_no_alu32 on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-21 fail Logs for test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-22 fail Logs for test_progs_no_alu32 on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-23 success Logs for test_progs_no_alu32_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-24 success Logs for test_progs_no_alu32_parallel on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-25 success Logs for test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-26 success Logs for test_progs_no_alu32_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-27 success Logs for test_progs_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-28 success Logs for test_progs_parallel on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-29 success Logs for test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-30 success Logs for test_progs_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-31 success Logs for test_verifier on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-32 success Logs for test_verifier on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-34 success Logs for test_verifier on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-35 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 llvm-16
bpf/vmtest-bpf-next-VM_Test-14 fail Logs for test_progs on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-19 fail Logs for test_progs_no_alu32 on aarch64 with llvm-16

Commit Message

Florian Westphal April 20, 2023, 12:44 p.m. UTC 
This is just to avoid ordering issues between multiple bpf programs,
this could be removed later in case it turns out to be too cautious.

bpf prog could still be shared with non-bpf hook, otherwise we'd have to
make conntrack hook registration fail just because a bpf program has
same priority.

Signed-off-by: Florian Westphal <fw@strlen.de>
---
 net/netfilter/core.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)
diff mbox series

Patch

diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index 358220b58521..f0783e42108b 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -119,6 +119,18 @@  nf_hook_entries_grow(const struct nf_hook_entries *old,
 		for (i = 0; i < old_entries; i++) {
 			if (orig_ops[i] != &dummy_ops)
 				alloc_entries++;
+
+			/* Restrict BPF hook type to force a unique priority, not
+			 * shared at attach time.
+			 *
+			 * This is mainly to avoid ordering issues between two
+			 * different bpf programs, this doesn't prevent a normal
+			 * hook at same priority as a bpf one (we don't want to
+			 * prevent defrag, conntrack, iptables etc from attaching).
+			 */
+			if (reg->priority == orig_ops[i]->priority &&
+			    reg->hook_ops_type == NF_HOOK_OP_BPF)
+				return ERR_PTR(-EBUSY);
 		}
 	}