kernel/linux.git/tools/bpf/bpftool, branch v6.1.186

bpftool: Use libbpf error code for flow dissector query

2026-07-24T13:54:38+00:00

[ Upstream commit 8a7f2bff2165e53595d1e91c160b340f978c0ab7 ] bpf_prog_query() returns a negative errno on failure. query_flow_dissector() currently closes the namespace fd and then reads errno to decide whether -EINVAL means that the running kernel does not support flow dissector queries. That errno check controls behavior, not just diagnostics: -EINVAL is handled as a non-fatal old-kernel case, while any other error makes bpftool net fail. The namespace fd is opened read-only, so close() is not expected to commonly fail in normal use. Still, the BPF_PROG_QUERY error is already available in err, and reading errno after an intervening close() is fragile. If close() does change errno, the compatibility branch may be based on close()'s error instead of the BPF_PROG_QUERY result. This was reproduced with an LD_PRELOAD fault injector that forced BPF_PROG_QUERY for BPF_FLOW_DISSECTOR to fail with EINVAL and then forced close() on the netns fd to fail with EIO. The unpatched bpftool reported "can't query prog: Input/output error". With this change, the same injected failure is handled as the intended non-fatal EINVAL compatibility case. Use the libbpf-returned error code instead. Keep the existing errno reset in the non-fatal path to preserve batch mode behavior. The success path is unchanged. Fixes: 7f0c57fec80f ("bpftool: show flow_dissector attachment status") Signed-off-by: Woojin Ji Signed-off-by: Andrii Nakryiko Acked-by: Leon Hwang Acked-by: Yonghong Song Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20260603003339.33791-1-random6.xyz@gmail.com Assisted-by: ChatGPT:gpt-5.5 Signed-off-by: Sasha Levin

bpftool: Fix truncated netlink dumps

2026-03-04T12:20:06+00:00

[ Upstream commit 3b39d73cc3379360a33eb583b17f21fe55e1288e ] Netlink requires that the recv buffer used during dumps is at least min(PAGE_SIZE, 8k) (see the man page). Otherwise the messages will get truncated. Make sure bpftool follows this requirement, avoid missing information on systems with large pages. Acked-by: Quentin Monnet Fixes: 7084566a236f ("tools/bpftool: Remove libbpf_internal.h usage in bpftool") Signed-off-by: Jakub Kicinski Link: https://lore.kernel.org/r/20260217194150.734701-1-kuba@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpftool: Fix -Wuninitialized-const-pointer warnings with clang >= 21

2025-12-06T21:12:16+00:00

[ Upstream commit 5612ea8b554375d45c14cbb0f8ea93ec5d172891 ] This fixes the build with -Werror -Wall. btf_dumper.c:71:31: error: variable 'finfo' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] 71 | info.func_info = ptr_to_u64(&finfo); | ^~~~~ prog.c:2294:31: error: variable 'func_info' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] 2294 | info.func_info = ptr_to_u64(&func_info); | v2: - Initialize instead of using memset. Signed-off-by: Tom Stellard Signed-off-by: Andrii Nakryiko Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20250917183847.318163-1-tstellar@redhat.com Signed-off-by: Sasha Levin

bpftool: Fix memory leak in dump_xx_nlmsg on realloc failure

2025-08-15T10:04:56+00:00

[ Upstream commit 99fe8af069a9fa5b09140518b1364e35713a642e ] In function dump_xx_nlmsg(), when realloc() fails to allocate memory, the original pointer to the buffer is overwritten with NULL. This causes a memory leak because the previously allocated buffer becomes unreachable without being freed. Fixes: 7900efc19214 ("tools/bpf: bpftool: improve output format for bpftool net") Signed-off-by: Yuan Chen Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/r/20250620012133.14819-1-chenyuan_fl@163.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpftool: Fix readlink usage in get_fd_type

2025-06-04T12:40:17+00:00

[ Upstream commit 0053f7d39d491b6138d7c526876d13885cbb65f1 ] The `readlink(path, buf, sizeof(buf))` call reads at most sizeof(buf) bytes and *does not* append null-terminator to buf. With respect to that, fix two pieces in get_fd_type: 1. Change the truncation check to contain sizeof(buf) rather than sizeof(path). 2. Append null-terminator to buf. Reported by Coverity. Signed-off-by: Viktor Malik Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20250129071857.75182-1-vmalik@redhat.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpftool: fix potential NULL pointer dereferencing in prog_dump()

2024-12-14T18:54:29+00:00

[ Upstream commit ef3ba8c258ee368a5343fa9329df85b4bcb9e8b5 ] A NULL pointer dereference could occur if ksyms is not properly checked before usage in the prog_dump() function. Fixes: b053b439b72a ("bpf: libbpf: bpftool: Print bpf_line_info during prog dump") Signed-off-by: Amir Mohammadi Reviewed-by: Quentin Monnet Acked-by: John Fastabend Link: https://lore.kernel.org/r/20241121083413.7214-1-amiremohamadi@yahoo.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpftool: Remove asserts from JIT disassembler

2024-12-14T18:54:29+00:00

[ Upstream commit 55b4de58d0e2aca810ed2b198a0173640300acf8 ] The JIT disassembler in bpftool is the only components (with the JSON writer) using asserts to check the return values of functions. But it does not do so in a consistent way, and diasm_print_insn() returns no value, although sometimes the operation failed. Remove the asserts, and instead check the return values, print messages on errors, and propagate the error to the caller from prog.c. Remove the inclusion of assert.h from jit_disasm.c, and also from map.c where it is unused. Signed-off-by: Quentin Monnet Tested-by: Niklas Söderlund Acked-by: Song Liu Link: https://lore.kernel.org/r/20221025150329.97371-3-quentin@isovalent.com Signed-off-by: Alexei Starovoitov Stable-dep-of: ef3ba8c258ee ("bpftool: fix potential NULL pointer dereferencing in prog_dump()") Signed-off-by: Sasha Levin

Revert "bpftool: Mount bpffs when pinmaps path not under the bpffs"

2024-08-14T11:52:50+00:00

This reverts commit 65dd9cbafec2f6f7908cebcab0386f750fc352af which is commit da5f8fd1f0d393d5eaaba9ad8c22d1c26bb2bf9b upstream. It breaks the build, so should be dropped. Reported-by: Salvatore Bonaccorso Link: https://lore.kernel.org/r/ZrSe8gZ_GyFv1knq@eldamar.lan Cc: Tao Chen Cc: Daniel Borkmann Cc: Quentin Monnet Cc: Sasha Levin Signed-off-by: Greg Kroah-Hartman

bpftool: Mount bpffs when pinmaps path not under the bpffs

2024-08-03T06:49:07+00:00

[ Upstream commit da5f8fd1f0d393d5eaaba9ad8c22d1c26bb2bf9b ] As Quentin said [0], BPF map pinning will fail if the pinmaps path is not under the bpffs, like: libbpf: specified path /home/ubuntu/test/sock_ops_map is not on BPF FS Error: failed to pin all maps [0] https://github.com/libbpf/bpftool/issues/146 Fixes: 3767a94b3253 ("bpftool: add pinmaps argument to the load/loadall") Signed-off-by: Tao Chen Signed-off-by: Daniel Borkmann Tested-by: Quentin Monnet Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20240702131150.15622-1-chen.dylane@gmail.com Signed-off-by: Sasha Levin

bpftool: Un-const bpf_func_info to fix it for llvm 17 and newer

2024-08-03T06:49:03+00:00

[ Upstream commit f4aba3471cfb9ccf69b476463f19b4c50fef6b14 ] LLVM 17 started treating const structs as constants: * https://github.com/llvm/llvm-project/commit/0b2d5b967d98 Combined with pointer laundering via ptr_to_u64, which takes a const ptr, but in reality treats the underlying memory as mutable, this makes clang always pass zero to btf__type_by_id, which breaks full name resolution. Disassembly before (LLVM 16) and after (LLVM 17): - 8b 75 cc mov -0x34(%rbp),%esi - e8 47 8d 02 00 call 3f5b0 + 31 f6 xor %esi,%esi + e8 a9 8c 02 00 call 3f510 It's a bigger project to fix this properly (and a question whether LLVM itself should detect this), but for right now let's just fix bpftool. For more information, see this thread in bpf mailing list: * https://lore.kernel.org/bpf/CABWYdi0ymezpYsQsPv7qzpx2fWuTkoD1-wG1eT-9x-TSREFrQg@mail.gmail.com/T/ Fixes: b662000aff84 ("bpftool: Adding support for BTF program names") Signed-off-by: Ivan Babrou Signed-off-by: Andrii Nakryiko Acked-by: Nick Desaulniers Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20240520225149.5517-1-ivan@cloudflare.com Signed-off-by: Sasha Levin