| Message ID | a4ef0d4a68fc858b34a81fd3f9877d9b6898eb77.1697439990.git.viresh.kumar@linaro.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | ba09dced696d3a9333d9f30a7296766480c1e79a |
| Headers | show |
| Series | xen: privcmd: Add ioeventfd and fix irqfd support | expand |
On 16.10.23 09:11, Viresh Kumar wrote: > Using indirect pointers in an ioctl command argument means that the > layout is architecture specific, in particular we can't use the same one > from 32-bit compat tasks. The general recommendation is to have __u64 > members and use u64_to_user_ptr() to access it from the kernel if we are > unable to avoid the pointers altogether. > > Fixes: f8941e6c4c71 ("xen: privcmd: Add support for irqfd") > Reported-by: Arnd Bergmann <arnd@kernel.org> > Closes: https://lore.kernel.org/all/268a2031-63b8-4c7d-b1e5-8ab83ca80b4a@app.fastmail.com/ > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Juergen Gross <jgross@suse.com> Juergen
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index 120af57999fc..5095bd1abea5 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -935,7 +935,7 @@ static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd) return -ENOMEM; dm_op = kirqfd + 1; - if (copy_from_user(dm_op, irqfd->dm_op, irqfd->size)) { + if (copy_from_user(dm_op, u64_to_user_ptr(irqfd->dm_op), irqfd->size)) { ret = -EFAULT; goto error_kfree; } diff --git a/include/uapi/xen/privcmd.h b/include/uapi/xen/privcmd.h index 375718ba4ab6..b143fafce84d 100644 --- a/include/uapi/xen/privcmd.h +++ b/include/uapi/xen/privcmd.h @@ -102,7 +102,7 @@ struct privcmd_mmap_resource { #define PRIVCMD_IRQFD_FLAG_DEASSIGN (1 << 0) struct privcmd_irqfd { - void __user *dm_op; + __u64 dm_op; __u32 size; /* Size of structure pointed by dm_op */ __u32 fd; __u32 flags;
Using indirect pointers in an ioctl command argument means that the layout is architecture specific, in particular we can't use the same one from 32-bit compat tasks. The general recommendation is to have __u64 members and use u64_to_user_ptr() to access it from the kernel if we are unable to avoid the pointers altogether. Fixes: f8941e6c4c71 ("xen: privcmd: Add support for irqfd") Reported-by: Arnd Bergmann <arnd@kernel.org> Closes: https://lore.kernel.org/all/268a2031-63b8-4c7d-b1e5-8ab83ca80b4a@app.fastmail.com/ Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- drivers/xen/privcmd.c | 2 +- include/uapi/xen/privcmd.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)