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authorHe Zhe <zhe.he@windriver.com>2018-09-29 18:45:50 +0200
committerPetr Mladek <pmladek@suse.com>2018-10-05 14:11:12 +0200
commit277fcdb2cfee38ccdbe07e705dbd4896ba0c9930 (patch)
tree22054985b786271e657881f2b14e2c0a33b3f737 /kernel/printk/printk.c
parentprintk: CON_PRINTBUFFER console registration is a bit racy (diff)
downloadlinux-277fcdb2cfee38ccdbe07e705dbd4896ba0c9930.tar.xz
linux-277fcdb2cfee38ccdbe07e705dbd4896ba0c9930.zip
printk: Fix panic caused by passing log_buf_len to command line
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. Link: http://lkml.kernel.org/r/1538239553-81805-1-git-send-email-zhe.he@windriver.com Cc: stable@vger.kernel.org Cc: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org Signed-off-by: He Zhe <zhe.he@windriver.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.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index c5b568c2d167..a14f15ad0f35 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1049,7 +1049,12 @@ 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)
+ return -EINVAL;
+
+ size = memparse(str, &str);
log_buf_len_update(size);