param: fix crash on bad kernel arguments

commit 3438cf549d2f3ee8e52c82acc8e2a9710ac21a5b upstream.

Currently if the user passes an invalid value on the kernel command line
then the kernel will crash during argument parsing. On most systems this
is very hard to debug because the console hasn't been initialized yet.

This is a regression due to commit 51e158c12aca ("param: hand arguments
after -- straight to init") which, in response to the systemd debug
controversy, made it possible to explicitly pass arguments to init. To
achieve this parse_args() was extended from simply returning an error
code to returning a pointer. Regretably the new init args logic does not
perform a proper validity check on the pointer resulting in a crash.

This patch fixes the validity check. Should the check fail then no arguments
will be passed to init. This is reasonable and matches how the kernel treats
its own arguments (i.e. no error recovery).

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

This commit is contained in:

Daniel Thompson

2014-11-11 16:29:46 +10:30

committed by

syphyr

parent 71b23d898f

commit 0d5cf975f5

1 changed files with 1 additions and 1 deletions

									
										2

init/main.c

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				@ -572,7 +572,7 @@ asmlinkage void __init start_kernel(void)

								  static_command_line, __start___param,

								  __stop___param - __start___param,

								  -1, -1, &unknown_bootoption);

					if (after_dashes)

					if (!IS_ERR_OR_NULL(after_dashes))

						parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,

							   set_init_arg);

param: fix crash on bad kernel arguments

2 init/main.c Unescape Escape View File

2

init/main.c

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