From: Arvind Sankar <nivedita@alum.mit.edu>
To: Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH v2 3/3] init/main.c: fix quoted value handling in unknown_bootoption
Date: Thu, 12 Dec 2019 13:00:23 -0500 [thread overview]
Message-ID: <20191212180023.24339-4-nivedita@alum.mit.edu> (raw)
In-Reply-To: <20191212180023.24339-1-nivedita@alum.mit.edu>
Commit a99cd1125189 ("init: fix bug where environment vars can't be
passed via boot args") introduced two minor bugs in unknown_bootoption
by factoring out the quoted value handling into a separate function.
When value is quoted, repair_env_string will move the value up 1 byte to
strip the quotes, so val in unknown_bootoption no longer points to the
actual location of the value.
The result is that an argument of the form param=".value" is mistakenly
treated as a potential module parameter and is not placed in init's
environment, and an argument of the form param="value" can result in a
duplicate environment variable: eg TERM="vt100" on the command line will
result in both TERM=linux and TERM=vt100 being placed into init's
environment.
Fix this by recording the length of the param before calling
repair_env_string instead of relying on val.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
---
init/main.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/init/main.c b/init/main.c
index a1febc3de582..efece9fe988e 100644
--- a/init/main.c
+++ b/init/main.c
@@ -255,7 +255,6 @@ static void __init repair_env_string(char *param, char *val)
else if (val == param+strlen(param)+2) {
val[-2] = '=';
memmove(val-1, val, strlen(val)+1);
- val--;
} else
BUG();
}
@@ -290,6 +289,8 @@ static int __init set_init_arg(char *param, char *val,
static int __init unknown_bootoption(char *param, char *val,
const char *unused, void *arg)
{
+ size_t len = strlen(param);
+
repair_env_string(param, val);
/* Handle obsolete-style parameters */
@@ -297,7 +298,7 @@ static int __init unknown_bootoption(char *param, char *val,
return 0;
/* Unused module parameter. */
- if (strchr(param, '.') && (!val || strchr(param, '.') < val))
+ if (strnchr(param, len, '.'))
return 0;
if (panic_later)
@@ -311,7 +312,7 @@ static int __init unknown_bootoption(char *param, char *val,
panic_later = "env";
panic_param = param;
}
- if (!strncmp(param, envp_init[i], val - param))
+ if (!strncmp(param, envp_init[i], len+1))
break;
}
envp_init[i] = param;
--
2.23.0
prev parent reply other threads:[~2019-12-12 18:00 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-23 21:08 [PATCH 0/3] init/main.c: minor cleanup/bugfix of envvar handling Arvind Sankar
2019-11-23 21:08 ` [PATCH 1/3] init/main.c: log arguments and environment passed to init Arvind Sankar
2019-11-23 21:08 ` [PATCH 2/3] init/main.c: remove unnecessary repair_env_string in do_initcall_level Arvind Sankar
2019-11-23 21:08 ` [PATCH 3/3] init/main.c: fix quoted value handling in unknown_bootoption Arvind Sankar
2019-11-23 21:20 ` [PATCH 0/3] init/main.c: minor cleanup/bugfix of envvar handling Randy Dunlap
2019-11-23 21:26 ` Arvind Sankar
2019-11-23 21:40 ` [PATCH RESEND " Arvind Sankar
2019-11-23 21:40 ` [PATCH RESEND 1/3] init/main.c: log arguments and environment passed to init Arvind Sankar
2019-11-23 21:40 ` [PATCH RESEND 2/3] init/main.c: remove unnecessary repair_env_string in do_initcall_level Arvind Sankar
2019-11-23 21:40 ` [PATCH RESEND 3/3] init/main.c: fix quoted value handling in unknown_bootoption Arvind Sankar
2019-11-27 19:25 ` [PATCH RESEND 0/3] init/main.c: minor cleanup/bugfix of envvar handling Arvind Sankar
2019-12-12 18:00 ` [PATCH v2 " Arvind Sankar
2019-12-12 18:00 ` [PATCH v2 1/3] init/main.c: log arguments and environment passed to init Arvind Sankar
2019-12-12 18:00 ` [PATCH v2 2/3] init/main.c: remove unnecessary repair_env_string in do_initcall_level Arvind Sankar
2019-12-12 18:00 ` Arvind Sankar [this message]
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