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authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2015-04-17 10:27:57 -0400
committerSteven Rostedt <rostedt@goodmis.org>2015-04-17 10:34:43 -0400
commit3193899d4dd54056f8c2e0b1e40dd6e2f0009f28 (patch)
tree8f118c5311094656325fff91c1a036d042ce46dc
parent84fce9db4d7eaebd6cb2ee30c15da6d4e4daf846 (diff)
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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 <sasha.levin@oracle.com> # via KASan Tested-by: Andrey Ryabinin <a.ryabinin@samsung.com> Fixes: 0c564a538aa9 "tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--kernel/trace/trace_events.c6
1 files changed, 6 insertions, 0 deletions
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;
}
/*