diff options
| author | Xiaoming Ni | 2021-01-23 21:02:16 -0800 |
|---|---|---|
| committer | Linus Torvalds | 2021-01-24 10:34:53 -0800 |
| commit | 697edcb0e4eadc41645fe88c991fe6a206b1a08d (patch) | |
| tree | 39c57588c621fc45710e5e011eaee876cf389534 | |
| parent | 785025820a6a565185ce9d47fdd8d23dbf91dee8 (diff) | |
proc_sysctl: fix oops caused by incorrect command parameters
The process_sysctl_arg() does not check whether val is empty before
invoking strlen(val). If the command line parameter () is incorrectly
configured and val is empty, oops is triggered.
For example:
"hung_task_panic=1" is incorrectly written as "hung_task_panic", oops is
triggered. The call stack is as follows:
Kernel command line: .... hung_task_panic
......
Call trace:
__pi_strlen+0x10/0x98
parse_args+0x278/0x344
do_sysctl_args+0x8c/0xfc
kernel_init+0x5c/0xf4
ret_from_fork+0x10/0x30
To fix it, check whether "val" is empty when "phram" is a sysctl field.
Error codes are returned in the failure branch, and error logs are
generated by parse_args().
Link: https://lkml.kernel.org/r/20210118133029.28580-1-nixiaoming@huawei.com
Fixes: 3db978d480e2843 ("kernel/sysctl: support setting sysctl parameters from kernel command line")
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: <stable@vger.kernel.org> [5.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/proc/proc_sysctl.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 317899222d7f..d2018f70d1fa 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -1770,6 +1770,12 @@ static int process_sysctl_arg(char *param, char *val, return 0; } + if (!val) + return -EINVAL; + len = strlen(val); + if (len == 0) + return -EINVAL; + /* * To set sysctl options, we use a temporary mount of proc, look up the * respective sys/ file and write to it. To avoid mounting it when no @@ -1811,7 +1817,6 @@ static int process_sysctl_arg(char *param, char *val, file, param, val); goto out; } - len = strlen(val); wret = kernel_write(file, val, len, &pos); if (wret < 0) { err = wret; |