| Message ID | 20211220032402.630240-1-wangborong@cdjrlc.com (mailing list archive) |
|---|---|
| State | Rejected, archived |
| Headers | show |
| Series | powerpc: use strscpy to copy strings | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 7 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 24 jobs. |
From: Jason Wang > Sent: 20 December 2021 03:24 > > The strlcpy should not be used because it doesn't limit the source > length. So that it will lead some potential bugs. > > But the strscpy doesn't require reading memory from the src string > beyond the specified "count" bytes, and since the return value is > easier to error-check than strlcpy()'s. In addition, the implementation > is robust to the string changing out from underneath it, unlike the > current strlcpy() implementation. > > Thus, replace strlcpy with strscpy. > > Signed-off-by: Jason Wang <wangborong@cdjrlc.com> > --- > arch/powerpc/platforms/pasemi/misc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/powerpc/platforms/pasemi/misc.c b/arch/powerpc/platforms/pasemi/misc.c > index 1bf65d02d3ba..06a1ffd43bfe 100644 > --- a/arch/powerpc/platforms/pasemi/misc.c > +++ b/arch/powerpc/platforms/pasemi/misc.c > @@ -35,7 +35,7 @@ static int __init find_i2c_driver(struct device_node *node, > for (i = 0; i < ARRAY_SIZE(i2c_devices); i++) { > if (!of_device_is_compatible(node, i2c_devices[i].of_device)) > continue; > - if (strlcpy(info->type, i2c_devices[i].i2c_type, > + if (strscpy(info->type, i2c_devices[i].i2c_type, > I2C_NAME_SIZE) >= I2C_NAME_SIZE) > return -ENOMEM; Isn't that the wrong overflow check? Doesn't strscpy() return a -ve errno value on failure (just to cause a different buffer overflow issue?) Not that any kind of overflow is actually possible in that over-engineered code fragment. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
diff --git a/arch/powerpc/platforms/pasemi/misc.c b/arch/powerpc/platforms/pasemi/misc.c index 1bf65d02d3ba..06a1ffd43bfe 100644 --- a/arch/powerpc/platforms/pasemi/misc.c +++ b/arch/powerpc/platforms/pasemi/misc.c @@ -35,7 +35,7 @@ static int __init find_i2c_driver(struct device_node *node, for (i = 0; i < ARRAY_SIZE(i2c_devices); i++) { if (!of_device_is_compatible(node, i2c_devices[i].of_device)) continue; - if (strlcpy(info->type, i2c_devices[i].i2c_type, + if (strscpy(info->type, i2c_devices[i].i2c_type, I2C_NAME_SIZE) >= I2C_NAME_SIZE) return -ENOMEM; return 0;
The strlcpy should not be used because it doesn't limit the source length. So that it will lead some potential bugs. But the strscpy doesn't require reading memory from the src string beyond the specified "count" bytes, and since the return value is easier to error-check than strlcpy()'s. In addition, the implementation is robust to the string changing out from underneath it, unlike the current strlcpy() implementation. Thus, replace strlcpy with strscpy. Signed-off-by: Jason Wang <wangborong@cdjrlc.com> --- arch/powerpc/platforms/pasemi/misc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)