The patch titled
Subject: vmcore: replace strncpy with strscpy_pad
has been added to the -mm mm-nonmm-unstable branch. Its filename is
vmcore-replace-strncpy-with-strscpy_pad.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/vmcore-replace-strncpy-with-strscpy_pad.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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From: Justin Stitt <justinstitt@xxxxxxxxxx>
Subject: vmcore: replace strncpy with strscpy_pad
Date: Mon, 01 Apr 2024 18:39:55 +0000
strncpy() is in the process of being replaced as it is deprecated [1].
We should move towards safer and less ambiguous string interfaces.
Looking at vmcoredd_header's definition:
| struct vmcoredd_header {
| __u32 n_namesz; /* Name size */
| __u32 n_descsz; /* Content size */
| __u32 n_type; /* NT_VMCOREDD */
| __u8 name[8]; /* LINUX\0\0\0 */
| __u8 dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Device dump's name */
| };
. we see that @name wants to be NUL-padded.
We're copying data->dump_name which is defined as:
| char dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Unique name of the dump */
. which shares the same size as vdd_hdr->dump_name. Let's make sure we
NUL-pad this as well.
Use strscpy_pad() which NUL-terminates and NUL-pads its destination
buffers. Specifically, use the new 2-argument version of strscpy_pad
introduced in Commit e6584c3964f2f ("string: Allow 2-argument
strscpy()").
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90
Link: https://lkml.kernel.org/r/20240401-strncpy-fs-proc-vmcore-c-v2-1-dd0a73f42635@xxxxxxxxxx
Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
Acked-by: Baoquan He <bhe@xxxxxxxxxx>
Cc: Dave Young <dyoung@xxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/vmcore.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
--- a/fs/proc/vmcore.c~vmcore-replace-strncpy-with-strscpy_pad
+++ a/fs/proc/vmcore.c
@@ -1370,9 +1370,8 @@ static void vmcoredd_write_header(void *
vdd_hdr->n_descsz = size + sizeof(vdd_hdr->dump_name);
vdd_hdr->n_type = NT_VMCOREDD;
- strncpy((char *)vdd_hdr->name, VMCOREDD_NOTE_NAME,
- sizeof(vdd_hdr->name));
- memcpy(vdd_hdr->dump_name, data->dump_name, sizeof(vdd_hdr->dump_name));
+ strscpy_pad(vdd_hdr->name, VMCOREDD_NOTE_NAME);
+ strscpy_pad(vdd_hdr->dump_name, data->dump_name);
}
/**
_
Patches currently in -mm which might be from justinstitt@xxxxxxxxxx are
vmcore-replace-strncpy-with-strscpy_pad.patch
