2022-07-12 01:13:16

by Jianglei Nie

Subject: [PATCH v4] proc/vmcore: fix potential memory leak in vmcore_init()

elfcorehdr_alloc() allocates a memory chunk for elfcorehdr_addr with
kzalloc(). If is_vmcore_usable() returns false, elfcorehdr_addr is a
predefined value. If parse_crash_elf_headers() occurs some error and
returns a negetive value, the elfcorehdr_addr should be released with
elfcorehdr_free().

We can fix by calling elfcorehdr_free() when parse_crash_elf_headers()
fails.

Signed-off-by: Jianglei Nie <[email protected]>
---
fs/proc/vmcore.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 4eaeb645e759..390515c249dd 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -1569,15 +1569,16 @@ static int __init vmcore_init(void)
rc = parse_crash_elf_headers();
if (rc) {
pr_warn("Kdump: vmcore not initialized\n");
- return rc;
+ goto fail;
}
- elfcorehdr_free(elfcorehdr_addr);
elfcorehdr_addr = ELFCORE_ADDR_ERR;

proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops);
if (proc_vmcore)
proc_vmcore->size = vmcore_size;
- return 0;
+fail:
+ elfcorehdr_free(elfcorehdr_addr);
+ return rc;
}
fs_initcall(vmcore_init);

--
2.25.1

2022-07-12 01:57:00

by Baoquan He

Subject: Re: [PATCH v4] proc/vmcore: fix potential memory leak in vmcore_init()

On 07/12/22 at 09:00am, Jianglei Nie wrote:
> elfcorehdr_alloc() allocates a memory chunk for elfcorehdr_addr with
> kzalloc(). If is_vmcore_usable() returns false, elfcorehdr_addr is a
> predefined value. If parse_crash_elf_headers() occurs some error and
^ s/occurs/gets/
occur is intransitive verb
> returns a negetive value, the elfcorehdr_addr should be released with
> elfcorehdr_free().
>
> fix by calling elfcorehdr_free() when parse_crash_elf_headers()
> fails.

Fix it by calling elfcorehdr_free() when parse_crash_elf_headers()
fails.

Other than above log concerns, you can add my ack when repost:

Acked-by: Baoquan He <[email protected]>

Note:
- Please also add change history so that people know what's happening
during reviewing. For this one, you can skip it.
- remember adding all people involved to CC.

>
> Signed-off-by: Jianglei Nie <[email protected]>
> ---
> fs/proc/vmcore.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
> index 4eaeb645e759..390515c249dd 100644
> --- a/fs/proc/vmcore.c
> +++ b/fs/proc/vmcore.c
> @@ -1569,15 +1569,16 @@ static int __init vmcore_init(void)
> rc = parse_crash_elf_headers();
> if (rc) {
> pr_warn("Kdump: vmcore not initialized\n");
> - return rc;
> + goto fail;
> }
> - elfcorehdr_free(elfcorehdr_addr);
> elfcorehdr_addr = ELFCORE_ADDR_ERR;
>
> proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops);
> if (proc_vmcore)
> proc_vmcore->size = vmcore_size;
> - return 0;
> +fail:
> + elfcorehdr_free(elfcorehdr_addr);
> + return rc;
> }
> fs_initcall(vmcore_init);
>
> --
> 2.25.1
>