| Message ID | 20250225092949.287300-2-thorsten.blum@linux.dev (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | btrfs: Replace deprecated strncpy() with strscpy_pad() | expand |
On Tue, Feb 25, 2025 at 10:29:49AM +0100, Thorsten Blum wrote: > strncpy() is deprecated for NUL-terminated destination buffers. Use > strscpy_pad() instead and don't zero-initialize the param array. > > Compile-tested only. > > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@vger.kernel.org > Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> > --- > fs/btrfs/sysfs.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c > index 53b846d99ece..b941fb37776d 100644 > --- a/fs/btrfs/sysfs.c > +++ b/fs/btrfs/sysfs.c > @@ -1330,13 +1330,13 @@ MODULE_PARM_DESC(read_policy, > > int btrfs_read_policy_to_enum(const char *str, s64 *value_ret) > { > - char param[32] = { 0 }; > + char param[32]; > char __maybe_unused *value_str; > > if (!str || strlen(str) == 0) > return 0; > > - strncpy(param, str, sizeof(param) - 1); > + strscpy_pad(param, str); I don't think we need the padding, so strscpy is probably ok. We copy input string to a temporary modifiable buffer and then match it against a table, so the NUL termination is ok.
On 25. Feb 2025, at 13:28, David Sterba wrote: > On Tue, Feb 25, 2025 at 10:29:49AM +0100, Thorsten Blum wrote: >> strncpy() is deprecated for NUL-terminated destination buffers. Use >> strscpy_pad() instead and don't zero-initialize the param array. >> >> Compile-tested only. >> >> Link: https://github.com/KSPP/linux/issues/90 >> Cc: linux-hardening@vger.kernel.org >> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> >> --- > > I don't think we need the padding, so strscpy is probably ok. We copy > input string to a temporary modifiable buffer and then match it against > a table, so the NUL termination is ok. Ok thanks, I'll submit a v2 later today.
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 53b846d99ece..b941fb37776d 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -1330,13 +1330,13 @@ MODULE_PARM_DESC(read_policy, int btrfs_read_policy_to_enum(const char *str, s64 *value_ret) { - char param[32] = { 0 }; + char param[32]; char __maybe_unused *value_str; if (!str || strlen(str) == 0) return 0; - strncpy(param, str, sizeof(param) - 1); + strscpy_pad(param, str); #ifdef CONFIG_BTRFS_EXPERIMENTAL /* Separate value from input in policy:value format. */
strncpy() is deprecated for NUL-terminated destination buffers. Use strscpy_pad() instead and don't zero-initialize the param array. Compile-tested only. Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> --- fs/btrfs/sysfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)