diff options
authorBorislav Petkov <bp@suse.de>2018-10-30 15:07:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-31 08:54:14 -0700
commitb49dec1cf8ff1e0b204dd2c30b95a92d75591146 (patch)
parent95c4fb78fb23081472465ca20d5d31c4b780ed82 (diff)
kernel/panic.c: filter out a potential trailing newline
If a call to panic() terminates the string with a \n , the result puts the closing brace ']---' on a newline because panic() itself adds \n too. Now, if one goes and removes the newline chars from all panic() invocations - and the stats right now look like this: ~300 calls with a \n ~500 calls without a \n one is destined to a neverending game of whack-a-mole because the usual thing to do is add a newline at the end of a string a function is supposed to print. Therefore, simply zap any \n at the end of the panic string to avoid touching so many places in the kernel. Link: http://lkml.kernel.org/r/20181009205019.2786-1-bp@alien8.de Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/panic.c b/kernel/panic.c
index 837a94b7024d..f6d549a29a5c 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -136,7 +136,7 @@ void panic(const char *fmt, ...)
static char buf[1024];
va_list args;
- long i, i_next = 0;
+ long i, i_next = 0, len;
int state = 0;
int old_cpu, this_cpu;
bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;
@@ -173,8 +173,12 @@ void panic(const char *fmt, ...)
va_start(args, fmt);
- vsnprintf(buf, sizeof(buf), fmt, args);
+ len = vscnprintf(buf, sizeof(buf), fmt, args);
+ if (len && buf[len - 1] == '\n')
+ buf[len - 1] = '\0';
pr_emerg("Kernel panic - not syncing: %s\n", buf);

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