[for-linus][PATCH 0/2] tracing: Fixes to bootconfig memory handling

[for-linus][PATCH 0/2] tracing: Fixes to bootconfig memory handling

[Steven Rostedt]

Some memory management fixes to the bootconfig code.

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
for-next

Head SHA1: 8e9f0934a07e699044d422ca9cfb553f25c72b41


Masami Hiramatsu (2):
      bootconfig: Fix to check the xbc_node is used before free it
      bootconfig: Free copied bootconfig data after boot

----
 init/main.c      | 8 ++++++++
 lib/bootconfig.c | 3 ++-
 2 files changed, 10 insertions(+), 1 deletion(-)

[for-linus][PATCH 1/2] bootconfig: Fix to check the xbc_node is used before free it

[Steven Rostedt]

From: Masami Hiramatsu <mhiramat@kernel.org>

Fix to check the xbc_node is used before calling memblock_free()
because passing NULL to phys_addr() will cause a panic.
This will happen if user doesn't pass any bootconfig to the
kernel, because kernel will call xbc_destroy_all() after
booting.

Link: https://lkml.kernel.org/r/163149460533.291098.7342418455457691240.stgit@devnote2

Fixes: 40caa127f3c7 ("init: bootconfig: Remove all bootconfig data when the init memory is removed")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 lib/bootconfig.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index f8419cff1147..4f8849706ef6 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -792,7 +792,8 @@ void __init xbc_destroy_all(void)
 	xbc_data = NULL;
 	xbc_data_size = 0;
 	xbc_node_num = 0;
-	memblock_free(__pa(xbc_nodes), sizeof(struct xbc_node) * XBC_NODE_MAX);
+	if (xbc_nodes)
+		memblock_free(__pa(xbc_nodes), sizeof(struct xbc_node) * XBC_NODE_MAX);
 	xbc_nodes = NULL;
 	brace_index = 0;
 }
-- 
2.32.0

Re: [for-linus][PATCH 1/2] bootconfig: Fix to check the xbc_node is used before free it

[Vlastimil Babka]

On 9/14/21 16:48, Steven Rostedt wrote:
> From: Masami Hiramatsu <mhiramat@kernel.org>
> 
> Fix to check the xbc_node is used before calling memblock_free()
> because passing NULL to phys_addr() will cause a panic.
> This will happen if user doesn't pass any bootconfig to the
> kernel, because kernel will call xbc_destroy_all() after
> booting.
> 
> Link: https://lkml.kernel.org/r/163149460533.291098.7342418455457691240.stgit@devnote2
> 
> Fixes: 40caa127f3c7 ("init: bootconfig: Remove all bootconfig data when the init memory is removed")
> Reported-by: kernel test robot <oliver.sang@intel.com>
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Should have replied here.

Tested-by: Vlastimil Babka <vbabka@suse.cz>

details:
https://lore.kernel.org/all/61ab2d0c-3313-aaab-514c-e15b7aa054a0@suse.cz/

> ---
>  lib/bootconfig.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/bootconfig.c b/lib/bootconfig.c
> index f8419cff1147..4f8849706ef6 100644
> --- a/lib/bootconfig.c
> +++ b/lib/bootconfig.c
> @@ -792,7 +792,8 @@ void __init xbc_destroy_all(void)
>  	xbc_data = NULL;
>  	xbc_data_size = 0;
>  	xbc_node_num = 0;
> -	memblock_free(__pa(xbc_nodes), sizeof(struct xbc_node) * XBC_NODE_MAX);
> +	if (xbc_nodes)
> +		memblock_free(__pa(xbc_nodes), sizeof(struct xbc_node) * XBC_NODE_MAX);
>  	xbc_nodes = NULL;
>  	brace_index = 0;
>  }
> 

Re: [for-linus][PATCH 1/2] bootconfig: Fix to check the xbc_node is used before free it

[Steven Rostedt]

On Tue, 14 Sep 2021 18:11:01 +0200
Vlastimil Babka <vbabka@suse.cz> wrote:

> Should have replied here.
> 
> Tested-by: Vlastimil Babka <vbabka@suse.cz>

Thanks, but I already sent a pull request to Linus.

Too late to add the tag. :-/


-- Steve

[for-linus][PATCH 2/2] bootconfig: Free copied bootconfig data after boot

[Steven Rostedt]

From: Masami Hiramatsu <mhiramat@kernel.org>

Free copied bootconfig data after booting kernel because that
data will not be used anymore.

commit 40caa127f3c7 ("init: bootconfig: Remove all bootconfig
data when the init memory is removed") freed the bootconfig
xbc_node array after booting kernel, but forgot to free the
bootconfig data itself. This fixes that to free the bootconfig
data too.

This also frees the bootconfig data if the bootconfig data
parsing failed.

Link: https://lkml.kernel.org/r/163151166275.369741.12201304720604568345.stgit@devnote2

Fixes: 40caa127f3c7 ("init: bootconfig: Remove all bootconfig data when the init memory is removed")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 init/main.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/init/main.c b/init/main.c
index d08caed17c7f..ddbcb372225a 100644
--- a/init/main.c
+++ b/init/main.c
@@ -319,6 +319,8 @@ static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
 #ifdef CONFIG_BOOT_CONFIG
 
 static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
+static void *init_xbc_data_copy __initdata;
+static phys_addr_t init_xbc_data_size __initdata;
 
 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
 
@@ -458,18 +460,24 @@ static void __init setup_boot_config(void)
 		else
 			pr_err("Failed to parse bootconfig: %s at %d.\n",
 				msg, pos);
+		memblock_free(__pa(copy), size + 1);
 	} else {
 		pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret);
 		/* keys starting with "kernel." are passed via cmdline */
 		extra_command_line = xbc_make_cmdline("kernel");
 		/* Also, "init." keys are init arguments */
 		extra_init_args = xbc_make_cmdline("init");
+		init_xbc_data_copy = copy;
+		init_xbc_data_size = size + 1;
 	}
 	return;
 }
 
 static void __init exit_boot_config(void)
 {
+	if (!init_xbc_data_copy)
+		return;
+	memblock_free(__pa(init_xbc_data_copy), init_xbc_data_size);
 	xbc_destroy_all();
 }
 
-- 
2.32.0