From ad5f0eb540d31d95e6eefe6e24af0fe1b1b393fa Mon Sep 17 00:00:00 2001 From: Justin Stitt Date: Mon, 1 Apr 2024 18:39:55 +0000 Subject: vmcore: replace strncpy with strscpy_pad 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@google.com Signed-off-by: Justin Stitt Acked-by: Baoquan He Cc: Dave Young Cc: Vivek Goyal Signed-off-by: Andrew Morton --- fs/proc/vmcore.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'fs/proc') diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 1fb213f379a5..5d08d4d159d3 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -1370,9 +1370,8 @@ static void vmcoredd_write_header(void *buf, struct vmcoredd_data *data, 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); } /** -- cgit v1.2.3