Messages in this thread | | | Date | Tue, 18 Sep 2018 11:51:49 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH] printk: Fix panic caused by passing log_buf_len to command line |
| |
On Tue, 18 Sep 2018 23:42:34 +0800 <zhe.he@windriver.com> wrote:
> From: He Zhe <zhe.he@windriver.com> > > log_buf_len_setup does not check input argument before passing it to > simple_strtoull. The argument would be a NULL pointer if "log_buf_len", > without its value, is set in command line and thus causes the following > panic. > > PANIC: early exception 0xe3 IP 10:ffffffffaaeacd0d error 0 cr2 0x0 > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc4-yocto-standard+ #1 > [ 0.000000] RIP: 0010:_parse_integer_fixup_radix+0xd/0x70 > ... > [ 0.000000] Call Trace: > [ 0.000000] simple_strtoull+0x29/0x70 > [ 0.000000] memparse+0x26/0x90 > [ 0.000000] log_buf_len_setup+0x17/0x22 > [ 0.000000] do_early_param+0x57/0x8e > [ 0.000000] parse_args+0x208/0x320 > [ 0.000000] ? rdinit_setup+0x30/0x30 > [ 0.000000] parse_early_options+0x29/0x2d > [ 0.000000] ? rdinit_setup+0x30/0x30 > [ 0.000000] parse_early_param+0x36/0x4d > [ 0.000000] setup_arch+0x336/0x99e > [ 0.000000] start_kernel+0x6f/0x4ee > [ 0.000000] x86_64_start_reservations+0x24/0x26 > [ 0.000000] x86_64_start_kernel+0x6f/0x72 > [ 0.000000] secondary_startup_64+0xa4/0xb0 > > This patch adds a check to prevent the panic, adds KBUILD_MODNAME to > prints and correct bare use of 'unsigned'.
Hi!
The addition of pr_fmt and the unsigned update should be a separate patch. This is a bug fix and only the bug fix should be included, as it is going to be backported.
Thanks!
-- Steve
> > Signed-off-by: He Zhe <zhe.he@windriver.com> > Cc: stable@vger.kernel.org > Cc: pmladek@suse.com > Cc: sergey.senozhatsky@gmail.com > Cc: rostedt@goodmis.org > --- > kernel/printk/printk.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c > index 9bf5404..f6d4030 100644 > --- a/kernel/printk/printk.c > +++ b/kernel/printk/printk.c > @@ -16,6 +16,8 @@ > * 01Mar01 Andrew Morton > */ > > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > + > #include <linux/kernel.h> > #include <linux/mm.h> > #include <linux/tty.h> > @@ -1048,7 +1050,14 @@ static void __init log_buf_len_update(unsigned size) > /* save requested log_buf_len since it's too early to process it */ > static int __init log_buf_len_setup(char *str) > { > - unsigned size = memparse(str, &str); > + unsigned int size; > + > + if (!str) { > + pr_err("Config string not provided\n"); > + return -EINVAL; > + } > + > + size = memparse(str, &str); > > log_buf_len_update(size); >
| |