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| author | Alexei Starovoitov <ast@kernel.org> | 2020-05-15 08:10:36 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-05-15 08:15:07 -0700 |
| commit | 59df9f1fb4977b40cfad8d07b0d5baeb3a07e22c (patch) | |
| tree | bb520b4c58247f567a586756c98ab5840d21f8f8 /lib/vsprintf.c | |
| parent | 6d74f64b922b8394dccc52576659cb0dc0a1da7b (diff) | |
| parent | b2a5212fb634561bb734c6356904e37f6665b955 (diff) | |
Merge branch 'restrict-bpf_probe_read'
Daniel Borkmann says:
====================
Small set of fixes in order to restrict BPF helpers for tracing which are
broken on archs with overlapping address ranges as per discussion in [0].
I've targetted this for -bpf tree so they can be routed as fixes. Thanks!
v1 -> v2:
- switch to reusable %pks, %pus format specifiers (Yonghong)
- fixate %s on kernel_ds probing for archs with overlapping addr space
[0] https://lore.kernel.org/bpf/CAHk-=wjJKo0GVixYLmqPn-Q22WFu0xHaBSjKEo7e7Yw72y5SPQ@mail.gmail.com/T/
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'lib/vsprintf.c')
| -rw-r--r-- | lib/vsprintf.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 7c488a1ce318..532b6606a18a 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -2168,6 +2168,10 @@ char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, * f full name * P node name, including a possible unit address * - 'x' For printing the address. Equivalent to "%lx". + * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of + * bpf_trace_printk() where [ku] prefix specifies either kernel (k) + * or user (u) memory to probe, and: + * s a string, equivalent to "%s" on direct vsnprintf() use * * ** When making changes please also update: * Documentation/core-api/printk-formats.rst @@ -2251,6 +2255,14 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, if (!IS_ERR(ptr)) break; return err_ptr(buf, end, ptr, spec); + case 'u': + case 'k': + switch (fmt[1]) { + case 's': + return string(buf, end, ptr, spec); + default: + return error_string(buf, end, "(einval)", spec); + } } /* default is to _not_ leak addresses, hash before printing */ |