diff options
| author | Christoph Hellwig <hch@lst.de> | 2020-06-09 07:34:50 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 19:39:15 +0300 |
| commit | 98a23609b10364a51a1bb3688f8dd1cd1aa94a9a (patch) | |
| tree | 8cf32f92fccd8cd5264434d42fa68dcba4c2ab3c /kernel/trace | |
| parent | 7676fbf21b5fa04341c8046c2cbcd1949293e7ec (diff) | |
| download | linux-98a23609b10364a51a1bb3688f8dd1cd1aa94a9a.tar.xz | |
maccess: always use strict semantics for probe_kernel_read
Except for historical confusion in the kprobes/uprobes and bpf tracers,
which has been fixed now, there is no good reason to ever allow user
memory accesses from probe_kernel_read. Switch probe_kernel_read to only
read from kernel memory.
[akpm@linux-foundation.org: update it for "mm, dump_page(): do not crash with invalid mapping pointer"]
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/20200521152301.2587579-17-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 2 | ||||
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 4 |
2 files changed, 3 insertions, 3 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 59cb19888891..e729c9e587a0 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -196,7 +196,7 @@ bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr) if (unlikely(ret < 0)) goto fail; - ret = probe_kernel_read_strict(dst, unsafe_ptr, size); + ret = probe_kernel_read(dst, unsafe_ptr, size); if (unlikely(ret < 0)) goto fail; return ret; diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 6a23b45613a2..ea8d0b094f1b 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1222,7 +1222,7 @@ fetch_store_strlen(unsigned long addr) #endif do { - ret = probe_kernel_read_strict(&c, (u8 *)addr + len, 1); + ret = probe_kernel_read(&c, (u8 *)addr + len, 1); len++; } while (c && ret == 0 && len < MAX_STRING_SIZE); @@ -1300,7 +1300,7 @@ probe_mem_read(void *dest, void *src, size_t size) if ((unsigned long)src < TASK_SIZE) return probe_mem_read_user(dest, src, size); #endif - return probe_kernel_read_strict(dest, src, size); + return probe_kernel_read(dest, src, size); } /* Note that we don't verify it, since the code does not come from user space */ |