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| author | Viktor Malik <vmalik@redhat.com> | 2025-01-29 08:18:57 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-04 14:32:34 +0200 |
| commit | 8079ba28438806f2d967ac5a08f236bf970feb44 (patch) | |
| tree | 39978b065b9afa5ba14ad959972d93358d2542bd | |
| parent | 2d16514e557f5eb3b23968a80771b3e65d2fc89f (diff) | |
| download | linux-8079ba28438806f2d967ac5a08f236bf970feb44.tar.gz linux-8079ba28438806f2d967ac5a08f236bf970feb44.tar.bz2 linux-8079ba28438806f2d967ac5a08f236bf970feb44.zip | |
bpftool: Fix readlink usage in get_fd_type
[ 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 <vmalik@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20250129071857.75182-1-vmalik@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | tools/bpf/bpftool/common.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c index a209f53901b8..91bf7575493b 100644 --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c @@ -283,10 +283,11 @@ int get_fd_type(int fd) p_err("can't read link type: %s", strerror(errno)); return -1; } - if (n == sizeof(path)) { + if (n == sizeof(buf)) { p_err("can't read link type: path too long!"); return -1; } + buf[n] = '\0'; if (strstr(buf, "bpf-map")) return BPF_OBJ_MAP; |