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bpf: Pointers beyond packet end. #334
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Master branch: 9600d62 |
Master branch: 7112d12 |
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This patch adds the verifier support to recognize inlined branch conditions. The LLVM knows that the branch evaluates to the same value, but the verifier couldn't track it. Hence causing valid programs to be rejected. The potential LLVM workaround: https://reviews.llvm.org/D87428 can have undesired side effects, since LLVM doesn't know that skb->data/data_end are being compared. LLVM has to introduce extra boolean variable and use inline_asm trick to force easier for the verifier assembly. Instead teach the verifier to recognize that r1 = skb->data; r1 += 10; r2 = skb->data_end; if (r1 > r2) { here r1 points beyond packet_end and subsequent if (r1 > r2) // always evaluates to "true". } Tested-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com>
Add a test that currently makes LLVM generate assembly code: $ llvm-objdump -S skb_pkt_end.o 0000000000000000 <main_prog>: ; if (skb_shorter(skb, ETH_IPV4_TCP_SIZE)) 0: 61 12 50 00 00 00 00 00 r2 = *(u32 *)(r1 + 80) 1: 61 14 4c 00 00 00 00 00 r4 = *(u32 *)(r1 + 76) 2: bf 43 00 00 00 00 00 00 r3 = r4 3: 07 03 00 00 36 00 00 00 r3 += 54 4: b7 01 00 00 00 00 00 00 r1 = 0 5: 2d 23 02 00 00 00 00 00 if r3 > r2 goto +2 <LBB0_2> 6: 07 04 00 00 0e 00 00 00 r4 += 14 ; if (skb_shorter(skb, ETH_IPV4_TCP_SIZE)) 7: bf 41 00 00 00 00 00 00 r1 = r4 0000000000000040 <LBB0_2>: 8: b4 00 00 00 ff ff ff ff w0 = -1 ; if (!(ip = get_iphdr(skb))) 9: 2d 23 05 00 00 00 00 00 if r3 > r2 goto +5 <LBB0_6> ; proto = ip->protocol; 10: 71 12 09 00 00 00 00 00 r2 = *(u8 *)(r1 + 9) ; if (proto != IPPROTO_TCP) 11: 56 02 03 00 06 00 00 00 if w2 != 6 goto +3 <LBB0_6> ; if (tcp->dest != 0) 12: 69 12 16 00 00 00 00 00 r2 = *(u16 *)(r1 + 22) 13: 56 02 01 00 00 00 00 00 if w2 != 0 goto +1 <LBB0_6> ; return tcp->urg_ptr; 14: 69 10 26 00 00 00 00 00 r0 = *(u16 *)(r1 + 38) 0000000000000078 <LBB0_6>: ; } 15: 95 00 00 00 00 00 00 00 exit Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com>
Add few assembly tests for packet comparison. Tested-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com>
Master branch: c365387 |
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=381673 irrelevant now. Closing PR. |
Add a test case which replaces an active ingress qdisc while keeping the miniq in-tact during the transition period to the new clsact qdisc. # ./vmtest.sh -- ./test_progs -t tc_link [...] ./test_progs -t tc_link [ 3.412871] bpf_testmod: loading out-of-tree module taints kernel. [ 3.413343] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel #332 tc_links_after:OK #333 tc_links_append:OK #334 tc_links_basic:OK #335 tc_links_before:OK #336 tc_links_chain_classic:OK #337 tc_links_chain_mixed:OK #338 tc_links_dev_chain0:OK #339 tc_links_dev_cleanup:OK #340 tc_links_dev_mixed:OK #341 tc_links_ingress:OK #342 tc_links_invalid:OK #343 tc_links_prepend:OK #344 tc_links_replace:OK #345 tc_links_revision:OK Summary: 14/0 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Martin KaFai Lau <martin.lau@kernel.org>
Add a test case which replaces an active ingress qdisc while keeping the miniq in-tact during the transition period to the new clsact qdisc. # ./vmtest.sh -- ./test_progs -t tc_link [...] ./test_progs -t tc_link [ 3.412871] bpf_testmod: loading out-of-tree module taints kernel. [ 3.413343] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel #332 tc_links_after:OK #333 tc_links_append:OK #334 tc_links_basic:OK #335 tc_links_before:OK #336 tc_links_chain_classic:OK #337 tc_links_chain_mixed:OK #338 tc_links_dev_chain0:OK #339 tc_links_dev_cleanup:OK #340 tc_links_dev_mixed:OK #341 tc_links_ingress:OK #342 tc_links_invalid:OK #343 tc_links_prepend:OK #344 tc_links_replace:OK #345 tc_links_revision:OK Summary: 14/0 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Martin KaFai Lau <martin.lau@kernel.org>
Add a test case which replaces an active ingress qdisc while keeping the miniq in-tact during the transition period to the new clsact qdisc. # ./vmtest.sh -- ./test_progs -t tc_link [...] ./test_progs -t tc_link [ 3.412871] bpf_testmod: loading out-of-tree module taints kernel. [ 3.413343] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel #332 tc_links_after:OK #333 tc_links_append:OK #334 tc_links_basic:OK #335 tc_links_before:OK #336 tc_links_chain_classic:OK #337 tc_links_chain_mixed:OK #338 tc_links_dev_chain0:OK #339 tc_links_dev_cleanup:OK #340 tc_links_dev_mixed:OK #341 tc_links_ingress:OK #342 tc_links_invalid:OK #343 tc_links_prepend:OK #344 tc_links_replace:OK #345 tc_links_revision:OK Summary: 14/0 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20240708133130.11609-2-daniel@iogearbox.net Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Currently, there is no terminator entry for exynosautov920_cmu_of_match, hence facing below KASAN warning, BUG: KASAN: global-out-of-bounds in of_match_node+0x120/0x13c Read of size 1 at addr ffffffe31cc9e628 by task swapper/0/1 CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0+ kernel-patches#334 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x94/0xec show_stack+0x18/0x24 dump_stack_lvl+0x90/0xd0 print_report+0x1f4/0x5b4 kasan_report+0xc8/0x110 __asan_report_load1_noabort+0x20/0x2c of_match_node+0x120/0x13c of_match_device+0x70/0xb4 platform_match+0xa0/0x25c __device_attach_driver+0x7c/0x2d4 bus_for_each_drv+0x100/0x188 __device_attach+0x174/0x364 device_initial_probe+0x14/0x20 bus_probe_device+0x128/0x158 device_add+0xb3c/0x10fc of_device_add+0xdc/0x150 of_platform_device_create_pdata+0x120/0x20c of_platform_bus_create+0x2bc/0x620 of_platform_populate+0x58/0x108 of_platform_default_populate_init+0x100/0x120 do_one_initcall+0x110/0x788 kernel_init_freeable+0x44c/0x61c kernel_init+0x24/0x1e4 ret_from_fork+0x10/0x20 The buggy address belongs to the variable: exynosautov920_cmu_of_match+0xc8/0x2c80 Add a dummy terminator entry at the end to assist of_match_node() in traversing up to the terminator entry without accessing an out-of-boundary index. Fixes: 485e13f ("clk: samsung: add top clock support for ExynosAuto v920 SoC") Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20240927102104.3268790-1-ruanjinjie@huawei.com [krzk: drop trailing comma] Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Pull request for series with
subject: bpf: Pointers beyond packet end.
version: 2
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=381673