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authorMasami Hiramatsu <mhiramat@kernel.org>2018-04-10 21:20:08 +0900
committerIngo Molnar <mingo@kernel.org>2018-04-10 20:14:11 +0200
commit50268a3d266ecfdd6c5873d62b2758d9732fc598 (patch)
tree8bb731fed7122c417891afeb5381290b10bd37d0
parent0eadcc7a7bc03e991d2da1cf88143fb7cc0342c1 (diff)
downloadlinux-50268a3d266ecfdd6c5873d62b2758d9732fc598.tar.bz2
tracing/uprobe_event: Fix strncpy corner case
Fix string fetch function to terminate with NUL. It is OK to drop the rest of string. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: security@kernel.org Cc: 范龙飞 <long7573@126.com> Fixes: 5baaa59ef09e ("tracing/probes: Implement 'memory' fetch method for uprobes") Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--kernel/trace/trace_uprobe.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 2014f4351ae0..0d450b40988e 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -151,6 +151,8 @@ static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
return;
ret = strncpy_from_user(dst, src, maxlen);
+ if (ret == maxlen)
+ dst[--ret] = '\0';
if (ret < 0) { /* Failed to fetch string */
((u8 *)get_rloc_data(dest))[0] = '\0';