6.6-stable review patch. If anyone has any objections, please let me know.
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From: Viresh Kumar viresh.kumar@linaro.org
[ Upstream commit 8dd765a5d769c521d73931850d1c8708fbc490cb ]
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.fastmai... Signed-off-by: Viresh Kumar viresh.kumar@linaro.org Reviewed-by: Juergen Gross jgross@suse.com Link: https://lore.kernel.org/r/a4ef0d4a68fc858b34a81fd3f9877d9b6898eb77.169743999... Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/xen/privcmd.c | 2 +- include/uapi/xen/privcmd.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index f00ad5f5f1d4a..da88173bac432 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 375718ba4ab62..b143fafce84db 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;