| Message ID | ZoV6Q6lWgVRqe7eh@p100 (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | wireguard: allowedips: Prevent unaligned memory accesses | expand |
Hi Helge, On Wed, Jul 03, 2024 at 06:20:19PM +0200, Helge Deller wrote: > On the parisc platform the Linux kernel issues kernel warnings because > swap_endian() tries to load a 128-bit IPv6 address from an unaligned > memory location: > Kernel: unaligned access to 0x55f4688c in wg_allowedips_insert_v6+0x2c/0x80 [wireguard] (iir 0xf3010df) > Kernel: unaligned access to 0x55f46884 in wg_allowedips_insert_v6+0x38/0x80 [wireguard] (iir 0xf2010dc) > > Avoid such unaligned memory accesses by instead using the > get_unaligned_be64() helper macro. > > Signed-off-by: Helge Deller <deller@gmx.de> > > diff --git a/drivers/net/wireguard/allowedips.c b/drivers/net/wireguard/allowedips.c > index 0ba714ca5185..daf967130b72 100644 > --- a/drivers/net/wireguard/allowedips.c > +++ b/drivers/net/wireguard/allowedips.c > @@ -15,8 +15,8 @@ static void swap_endian(u8 *dst, const u8 *src, u8 bits) > if (bits == 32) { > *(u32 *)dst = be32_to_cpu(*(const __be32 *)src); > } else if (bits == 128) { > - ((u64 *)dst)[0] = be64_to_cpu(((const __be64 *)src)[0]); > - ((u64 *)dst)[1] = be64_to_cpu(((const __be64 *)src)[1]); > + ((u64 *)dst)[0] = get_unaligned_be64(src); Ahh, right, in6_addr only has a u32 member, not a u64 member, so that's potentially unaligned. > + ((u64 *)dst)[1] = get_unaligned_be64(src[8]); src[8] is not correct, however. (This crashes; did you test it?) I've fixed it up and put it in the wireguard tree: https://git.kernel.org/pub/scm/linux/kernel/git/zx2c4/wireguard-linux.git/commit/?id=ad3d9eef8e1b304b243e63124581f97c88ce7ff9 I'll push this up to net.git soon. Thanks for the patch. Jason
diff --git a/drivers/net/wireguard/allowedips.c b/drivers/net/wireguard/allowedips.c index 0ba714ca5185..daf967130b72 100644 --- a/drivers/net/wireguard/allowedips.c +++ b/drivers/net/wireguard/allowedips.c @@ -15,8 +15,8 @@ static void swap_endian(u8 *dst, const u8 *src, u8 bits) if (bits == 32) { *(u32 *)dst = be32_to_cpu(*(const __be32 *)src); } else if (bits == 128) { - ((u64 *)dst)[0] = be64_to_cpu(((const __be64 *)src)[0]); - ((u64 *)dst)[1] = be64_to_cpu(((const __be64 *)src)[1]); + ((u64 *)dst)[0] = get_unaligned_be64(src); + ((u64 *)dst)[1] = get_unaligned_be64(src[8]); } }
On the parisc platform the Linux kernel issues kernel warnings because swap_endian() tries to load a 128-bit IPv6 address from an unaligned memory location: Kernel: unaligned access to 0x55f4688c in wg_allowedips_insert_v6+0x2c/0x80 [wireguard] (iir 0xf3010df) Kernel: unaligned access to 0x55f46884 in wg_allowedips_insert_v6+0x38/0x80 [wireguard] (iir 0xf2010dc) Avoid such unaligned memory accesses by instead using the get_unaligned_be64() helper macro. Signed-off-by: Helge Deller <deller@gmx.de>