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| author | Christoph Hellwig <hch@lst.de> | 2020-06-08 21:34:33 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:39:15 -0700 |
| commit | aec6ce59133edc4ac04f7d4e2556fdf047becb62 (patch) | |
| tree | 0df9a7a3646ed283d5c353a6a25099bc027c0409 /kernel | |
| parent | d7b2977b816223a884814eea46fbe38e192cec4c (diff) | |
| download | linux-aec6ce59133edc4ac04f7d4e2556fdf047becb62.tar.bz2 | |
bpf: handle the compat string in bpf_trace_copy_string better
User the proper helper for kernel or userspace addresses based on
TASK_SIZE instead of the dangerous strncpy_from_unsafe function.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-13-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 60e82c7b8122..a2efbdad434b 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -334,8 +334,11 @@ static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype, switch (fmt_ptype) { case 's': #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE - strncpy_from_unsafe(buf, unsafe_ptr, bufsz); - break; + if ((unsigned long)unsafe_ptr < TASK_SIZE) { + strncpy_from_user_nofault(buf, user_ptr, bufsz); + break; + } + fallthrough; #endif case 'k': strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz); |