| Message ID | 1511821819-5496-2-git-send-email-me@tobin.cc |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | kallsyms: don't leak address when printing symbol | expand |
I reordered the To's and CC's, I hope this doesn't break threading. (clearly I haven't groked email yet :( ) On Tue, Nov 28, 2017 at 09:30:17AM +1100, Tobin C. Harding wrote: > Currently if kallsyms_lookup() fails to find the symbol then the address > is printed. This potentially leaks sensitive information. Instead of > printing the address we can return an error, giving the calling code the > option to print the address or print some sanitized message. > > Return error instead of printing address to argument buffer. Leave > buffer in a sane state. > > Signed-off-by: Tobin C. Harding <me@tobin.cc> > --- > kernel/kallsyms.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c > index 531ffa984bc2..4bfa4ee3ce93 100644 > --- a/kernel/kallsyms.c > +++ b/kernel/kallsyms.c > @@ -394,8 +394,10 @@ static int __sprint_symbol(char *buffer, unsigned long address, > > address += symbol_offset; > name = kallsyms_lookup(address, &size, &offset, &modname, buffer); > - if (!name) > - return sprintf(buffer, "0x%lx", address - symbol_offset); > + if (!name) { > + buffer[0] = '\0'; > + return -1; > + } > > if (name != buffer) > strcpy(buffer, name); > -- > 2.7.4 > Do you want a Suggested-by: tag for this patch Steve? I mentioned you in the cover letter but as far as going into the git history I'm not entirely sure on the protocol for adding suggested-by. The kernel docs say not to add it without authorization, so ... thanks, Tobin.
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 531ffa984bc2..4bfa4ee3ce93 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -394,8 +394,10 @@ static int __sprint_symbol(char *buffer, unsigned long address, address += symbol_offset; name = kallsyms_lookup(address, &size, &offset, &modname, buffer); - if (!name) - return sprintf(buffer, "0x%lx", address - symbol_offset); + if (!name) { + buffer[0] = '\0'; + return -1; + } if (name != buffer) strcpy(buffer, name);
Currently if kallsyms_lookup() fails to find the symbol then the address is printed. This potentially leaks sensitive information. Instead of printing the address we can return an error, giving the calling code the option to print the address or print some sanitized message. Return error instead of printing address to argument buffer. Leave buffer in a sane state. Signed-off-by: Tobin C. Harding <me@tobin.cc> --- kernel/kallsyms.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)