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| author | Nathan Chancellor <natechancellor@gmail.com> | 2020-01-30 15:16:44 -0700 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2020-02-11 13:01:00 +0100 |
| commit | 5661dd95a2958634485bb1a53f90a6ab621d4b0c (patch) | |
| tree | 84d284668a4b97f8be8a83e36ce2206d7e1d30a7 /kernel/printk/printk.c | |
| parent | a4fe2b4d87c9f2298ae6a641a7a64bc941d079d0 (diff) | |
| download | linux-5661dd95a2958634485bb1a53f90a6ab621d4b0c.tar.bz2 | |
printk: Convert a use of sprintf to snprintf in console_unlock
When CONFIG_PRINTK is disabled (e.g. when building allnoconfig), clang
warns:
../kernel/printk/printk.c:2416:10: warning: 'sprintf' will always
overflow; destination buffer has size 0, but format string expands to at
least 33 [-Wfortify-source]
len = sprintf(text,
^
1 warning generated.
It is not wrong; text has a zero size when CONFIG_PRINTK is disabled
because LOG_LINE_MAX and PREFIX_MAX are both zero. Change to snprintf so
that this case is explicitly handled without any risk of overflow.
Link: https://github.com/ClangBuiltLinux/linux/issues/846
Link: https://github.com/llvm/llvm-project/commit/6d485ff455ea2b37fef9e06e426dae6c1241b231
Link: http://lkml.kernel.org/r/20200130221644.2273-1-natechancellor@gmail.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Cc: clang-built-linux@googlegroups.com
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Diffstat (limited to 'kernel/printk/printk.c')
| -rw-r--r-- | kernel/printk/printk.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index fada22dc4ab6..a44094727a5c 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2413,9 +2413,9 @@ again: printk_safe_enter_irqsave(flags); raw_spin_lock(&logbuf_lock); if (console_seq < log_first_seq) { - len = sprintf(text, - "** %llu printk messages dropped **\n", - log_first_seq - console_seq); + len = snprintf(text, sizeof(text), + "** %llu printk messages dropped **\n", + log_first_seq - console_seq); /* messages are gone, move to first one */ console_seq = log_first_seq; |