diff mbox series

[v2,bpf-next,7/8] bpf, sockmap: Several fixes to bpf_msg_pop_data

Message ID 20241106222520.527076-8-zijianzhang@bytedance.com (mailing list archive)
State Accepted
Commit 5d609ba262475db450ba69b8e8a557bd768ac07a
Delegated to: BPF
Headers show
Series Fixes to bpf_msg_push/pop_data and test_sockmap | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for bpf-next
netdev/apply fail Patch does not apply to bpf-next-0
bpf/vmtest-bpf-net-PR success PR summary
bpf/vmtest-bpf-net-VM_Test-0 success Logs for Lint
bpf/vmtest-bpf-net-VM_Test-2 success Logs for Unittests
bpf/vmtest-bpf-net-VM_Test-3 success Logs for Validate matrix.py
bpf/vmtest-bpf-net-VM_Test-1 success Logs for ShellCheck
bpf/vmtest-bpf-net-VM_Test-5 success Logs for aarch64-gcc / build-release
bpf/vmtest-bpf-net-VM_Test-4 success Logs for aarch64-gcc / build / build for aarch64 with gcc
bpf/vmtest-bpf-net-VM_Test-10 success Logs for aarch64-gcc / veristat
bpf/vmtest-bpf-net-VM_Test-9 success Logs for aarch64-gcc / test (test_verifier, false, 360) / test_verifier on aarch64 with gcc
bpf/vmtest-bpf-net-VM_Test-12 success Logs for s390x-gcc / build-release
bpf/vmtest-bpf-net-VM_Test-11 success Logs for s390x-gcc / build / build for s390x with gcc
bpf/vmtest-bpf-net-VM_Test-6 success Logs for aarch64-gcc / test (test_maps, false, 360) / test_maps on aarch64 with gcc
bpf/vmtest-bpf-net-VM_Test-7 success Logs for aarch64-gcc / test (test_progs, false, 360) / test_progs on aarch64 with gcc
bpf/vmtest-bpf-net-VM_Test-15 success Logs for s390x-gcc / test (test_verifier, false, 360) / test_verifier on s390x with gcc
bpf/vmtest-bpf-net-VM_Test-16 success Logs for s390x-gcc / veristat
bpf/vmtest-bpf-net-VM_Test-17 success Logs for set-matrix
bpf/vmtest-bpf-net-VM_Test-18 success Logs for x86_64-gcc / build / build for x86_64 with gcc
bpf/vmtest-bpf-net-VM_Test-19 success Logs for x86_64-gcc / build-release
bpf/vmtest-bpf-net-VM_Test-20 success Logs for x86_64-gcc / test (test_maps, false, 360) / test_maps on x86_64 with gcc
bpf/vmtest-bpf-net-VM_Test-21 success Logs for x86_64-gcc / test (test_progs, false, 360) / test_progs on x86_64 with gcc
bpf/vmtest-bpf-net-VM_Test-22 success Logs for x86_64-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-net-VM_Test-23 success Logs for x86_64-gcc / test (test_progs_no_alu32_parallel, true, 30) / test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-net-VM_Test-24 success Logs for x86_64-gcc / test (test_progs_parallel, true, 30) / test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-net-VM_Test-25 success Logs for x86_64-gcc / test (test_verifier, false, 360) / test_verifier on x86_64 with gcc
bpf/vmtest-bpf-net-VM_Test-26 success Logs for x86_64-gcc / veristat / veristat on x86_64 with gcc
bpf/vmtest-bpf-net-VM_Test-27 success Logs for x86_64-llvm-17 / build / build for x86_64 with llvm-17
bpf/vmtest-bpf-net-VM_Test-28 success Logs for x86_64-llvm-17 / build-release / build for x86_64 with llvm-17-O2
bpf/vmtest-bpf-net-VM_Test-29 success Logs for x86_64-llvm-17 / test (test_maps, false, 360) / test_maps on x86_64 with llvm-17
bpf/vmtest-bpf-net-VM_Test-32 success Logs for x86_64-llvm-17 / test (test_verifier, false, 360) / test_verifier on x86_64 with llvm-17
bpf/vmtest-bpf-net-VM_Test-33 success Logs for x86_64-llvm-17 / veristat
bpf/vmtest-bpf-net-VM_Test-34 success Logs for x86_64-llvm-18 / build / build for x86_64 with llvm-18
bpf/vmtest-bpf-net-VM_Test-35 success Logs for x86_64-llvm-18 / build-release / build for x86_64 with llvm-18-O2
bpf/vmtest-bpf-net-VM_Test-36 success Logs for x86_64-llvm-18 / test (test_maps, false, 360) / test_maps on x86_64 with llvm-18
bpf/vmtest-bpf-net-VM_Test-41 success Logs for x86_64-llvm-18 / veristat
bpf/vmtest-bpf-net-VM_Test-8 success Logs for aarch64-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on aarch64 with gcc
bpf/vmtest-bpf-net-VM_Test-14 success Logs for s390x-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on s390x with gcc
bpf/vmtest-bpf-net-VM_Test-30 success Logs for x86_64-llvm-17 / test (test_progs, false, 360) / test_progs on x86_64 with llvm-17
bpf/vmtest-bpf-net-VM_Test-31 success Logs for x86_64-llvm-17 / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with llvm-17
bpf/vmtest-bpf-net-VM_Test-37 success Logs for x86_64-llvm-18 / test (test_progs, false, 360) / test_progs on x86_64 with llvm-18
bpf/vmtest-bpf-net-VM_Test-38 success Logs for x86_64-llvm-18 / test (test_progs_cpuv4, false, 360) / test_progs_cpuv4 on x86_64 with llvm-18
bpf/vmtest-bpf-net-VM_Test-39 success Logs for x86_64-llvm-18 / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with llvm-18
bpf/vmtest-bpf-net-VM_Test-40 success Logs for x86_64-llvm-18 / test (test_verifier, false, 360) / test_verifier on x86_64 with llvm-18
bpf/vmtest-bpf-net-VM_Test-13 success Logs for s390x-gcc / test (test_progs, false, 360) / test_progs on s390x with gcc

Commit Message

Zijian Zhang Nov. 6, 2024, 10:25 p.m. UTC 
From: Zijian Zhang <zijianzhang@bytedance.com>

Several fixes to bpf_msg_pop_data,
1. In sk_msg_shift_left, we should put_page
2. if (len == 0), return early is better
3. pop the entire sk_msg (last == msg->sg.size) should be supported
4. Fix for the value of variable "a"
5. In sk_msg_shift_left, after shifting, i has already pointed to the next
element. Addtional sk_msg_iter_var_next may result in BUG.

Fixes: 7246d8ed4dcc ("bpf: helper to pop data from messages")
Signed-off-by: Zijian Zhang <zijianzhang@bytedance.com>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
---
 net/core/filter.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/net/core/filter.c b/net/core/filter.c
index 4fae427aa5ca..fba445b96de8 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2919,8 +2919,10 @@  static const struct bpf_func_proto bpf_msg_push_data_proto = {
 
 static void sk_msg_shift_left(struct sk_msg *msg, int i)
 {
+	struct scatterlist *sge = sk_msg_elem(msg, i);
 	int prev;
 
+	put_page(sg_page(sge));
 	do {
 		prev = i;
 		sk_msg_iter_var_next(i);
@@ -2957,6 +2959,9 @@  BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 	if (unlikely(flags))
 		return -EINVAL;
 
+	if (unlikely(len == 0))
+		return 0;
+
 	/* First find the starting scatterlist element */
 	i = msg->sg.start;
 	do {
@@ -2969,7 +2974,7 @@  BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 	} while (i != msg->sg.end);
 
 	/* Bounds checks: start and pop must be inside message */
-	if (start >= offset + l || last >= msg->sg.size)
+	if (start >= offset + l || last > msg->sg.size)
 		return -EINVAL;
 
 	space = MAX_MSG_FRAGS - sk_msg_elem_used(msg);
@@ -2998,12 +3003,12 @@  BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 	 */
 	if (start != offset) {
 		struct scatterlist *nsge, *sge = sk_msg_elem(msg, i);
-		int a = start;
+		int a = start - offset;
 		int b = sge->length - pop - a;
 
 		sk_msg_iter_var_next(i);
 
-		if (pop < sge->length - a) {
+		if (b > 0) {
 			if (space) {
 				sge->length = a;
 				sk_msg_shift_right(msg, i);
@@ -3022,7 +3027,6 @@  BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 				if (unlikely(!page))
 					return -ENOMEM;
 
-				sge->length = a;
 				orig = sg_page(sge);
 				from = sg_virt(sge);
 				to = page_address(page);
@@ -3032,7 +3036,7 @@  BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 				put_page(orig);
 			}
 			pop = 0;
-		} else if (pop >= sge->length - a) {
+		} else {
 			pop -= (sge->length - a);
 			sge->length = a;
 		}
@@ -3066,7 +3070,6 @@  BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 			pop -= sge->length;
 			sk_msg_shift_left(msg, i);
 		}
-		sk_msg_iter_var_next(i);
 	}
 
 	sk_mem_uncharge(msg->sk, len - pop);