Commit b49dec1c authored by Borislav Petkov's avatar Borislav Petkov Committed by Linus Torvalds

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.deSigned-off-by: default avatarBorislav Petkov <bp@suse.de>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 95c4fb78
...@@ -136,7 +136,7 @@ void panic(const char *fmt, ...) ...@@ -136,7 +136,7 @@ void panic(const char *fmt, ...)
{ {
static char buf[1024]; static char buf[1024];
va_list args; va_list args;
long i, i_next = 0; long i, i_next = 0, len;
int state = 0; int state = 0;
int old_cpu, this_cpu; int old_cpu, this_cpu;
bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers; bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;
...@@ -173,8 +173,12 @@ void panic(const char *fmt, ...) ...@@ -173,8 +173,12 @@ void panic(const char *fmt, ...)
console_verbose(); console_verbose();
bust_spinlocks(1); bust_spinlocks(1);
va_start(args, fmt); va_start(args, fmt);
vsnprintf(buf, sizeof(buf), fmt, args); len = vscnprintf(buf, sizeof(buf), fmt, args);
va_end(args); va_end(args);
if (len && buf[len - 1] == '\n')
buf[len - 1] = '\0';
pr_emerg("Kernel panic - not syncing: %s\n", buf); pr_emerg("Kernel panic - not syncing: %s\n", buf);
#ifdef CONFIG_DEBUG_BUGVERBOSE #ifdef CONFIG_DEBUG_BUGVERBOSE
/* /*
......
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