diff options
| author | Kees Cook <keescook@chromium.org> | 2020-07-02 20:49:23 +0200 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2020-07-09 00:59:57 +0200 |
| commit | 160251842cd35a75edfb0a1d76afa3eb674ff40a (patch) | |
| tree | a1ce82f3b8d23a325c151bd998b815af9574617c /include | |
| parent | Linux 5.8-rc2 (diff) | |
| download | linux-160251842cd35a75edfb0a1d76afa3eb674ff40a.tar.xz linux-160251842cd35a75edfb0a1d76afa3eb674ff40a.zip | |
kallsyms: Refactor kallsyms_show_value() to take cred
In order to perform future tests against the cred saved during open(),
switch kallsyms_show_value() to operate on a cred, and have all current
callers pass current_cred(). This makes it very obvious where callers
are checking the wrong credential in their "read" contexts. These will
be fixed in the coming patches.
Additionally switch return value to bool, since it is always used as a
direct permission check, not a 0-on-success, negative-on-error style
function return.
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/filter.h | 2 | ||||
| -rw-r--r-- | include/linux/kallsyms.h | 5 |
2 files changed, 4 insertions, 3 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h index 259377723603..55104f6c78e8 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -889,7 +889,7 @@ static inline bool bpf_dump_raw_ok(void) /* Reconstruction of call-sites is dependent on kallsyms, * thus make dump the same restriction. */ - return kallsyms_show_value() == 1; + return kallsyms_show_value(current_cred()); } struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h index 98338dc6b5d2..481273f0c72d 100644 --- a/include/linux/kallsyms.h +++ b/include/linux/kallsyms.h @@ -18,6 +18,7 @@ #define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s]") + (KSYM_NAME_LEN - 1) + \ 2*(BITS_PER_LONG*3/10) + (MODULE_NAME_LEN - 1) + 1) +struct cred; struct module; static inline int is_kernel_inittext(unsigned long addr) @@ -98,7 +99,7 @@ int lookup_symbol_name(unsigned long addr, char *symname); int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name); /* How and when do we show kallsyms values? */ -extern int kallsyms_show_value(void); +extern bool kallsyms_show_value(const struct cred *cred); #else /* !CONFIG_KALLSYMS */ @@ -158,7 +159,7 @@ static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, u return -ERANGE; } -static inline int kallsyms_show_value(void) +static inline bool kallsyms_show_value(const struct cred *cred) { return false; } |