From: Steven Rostedt (Red Hat) Date: Fri, 17 Apr 2015 14:27:57 +0000 (-0400) Subject: tracing: Fix possible out of bounds memory access when parsing enums X-Git-Tag: v4.1-rc1~37^2 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=3193899d4dd54056f8c2e0b1e40dd6e2f0009f28;p=linux.git tracing: Fix possible out of bounds memory access when parsing enums The code that replaces the enum names with the enum values in the tracepoints' format files could possible miss the end of string nul character. This was caused by processing things like backslashes, quotes and other tokens. After processing the tokens, a check for the nul character needed to be done before continuing the loop, because the loop incremented the pointer before doing the check, which could bypass the nul character. Link: http://lkml.kernel.org/r/552E661D.5060502@oracle.com Reported-by: Sasha Levin # via KASan Tested-by: Andrey Ryabinin Fixes: 0c564a538aa9 "tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values" Signed-off-by: Steven Rostedt --- diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 36a957c996c7..b49c107f82ac 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1760,6 +1760,8 @@ static void update_event_printk(struct ftrace_event_call *call, ptr++; /* Check for alpha chars like ULL */ } while (isalnum(*ptr)); + if (!*ptr) + break; /* * A number must have some kind of delimiter after * it, and we can ignore that too. @@ -1786,12 +1788,16 @@ static void update_event_printk(struct ftrace_event_call *call, do { ptr++; } while (isalnum(*ptr) || *ptr == '_'); + if (!*ptr) + break; /* * If what comes after this variable is a '.' or * '->' then we can continue to ignore that string. */ if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) { ptr += *ptr == '.' ? 1 : 2; + if (!*ptr) + break; goto skip_more; } /*