Messages in this thread Patch in this message | | | From | "Tobin C. Harding" <> | Subject | [RFC 1/3] kallsyms: don't leak address when symbol not found | Date | Tue, 28 Nov 2017 09:30:17 +1100 |
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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
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