The libaio library may set up I/O completion callback functions for I/O requests. The callback function pointer is stored in the data field of the io_event struct, and the pointer to the original iocb struct is stored in the obj field. Therefore, both the data and obj fields of the io_event struct might hold user pointers.
In the PCuABI, a user pointer is a 129-bit capability, so the __u64 type is not big enough to hold it. Use the __kernel_uintptr_t type instead, which is big enough on the affected architectures while remaining 64-bit on others. Additionally, use the special copy routine when copying user pointers to userspace.
Signed-off-by: Tudor Cretu tudor.cretu@arm.com --- fs/aio.c | 24 ++++++++++++------------ include/uapi/linux/aio_abi.h | 10 +++++----- 2 files changed, 17 insertions(+), 17 deletions(-)
diff --git a/fs/aio.c b/fs/aio.c index 7b2733b0f773..82f06f7b0df8 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -331,9 +331,9 @@ static int copy_io_events_to_user(struct kioctx *ctx, return copy_to_user((struct compat_io_event __user *)event_array + offset, (struct compat_io_event *)ctx->ring->io_events + ring_head, sizeof(struct compat_io_event) * nr); - return copy_to_user(event_array + offset, - ctx->ring->io_events + ring_head, - sizeof(struct io_event) * nr); + return copy_to_user_with_ptr(event_array + offset, + ctx->ring->io_events + ring_head, + sizeof(struct io_event) * nr); }
static void copy_io_event_to_ring(struct kioctx *ctx, @@ -344,8 +344,8 @@ static void copy_io_event_to_ring(struct kioctx *ctx, struct compat_io_event *compat_ring_event = (struct compat_io_event *)ctx->ring->io_events + ring_idx;
- compat_ring_event->data = native_event->data; - compat_ring_event->obj = native_event->obj; + compat_ring_event->data = (__u64)native_event->data; + compat_ring_event->obj = (__u64)native_event->obj; compat_ring_event->res = native_event->res; compat_ring_event->res2 = native_event->res2; flush_kernel_vmap_range(compat_ring_event, sizeof(struct compat_io_event)); @@ -1236,9 +1236,10 @@ static void aio_complete(struct aio_kiocb *iocb) if (++tail >= ctx->nr_events) tail = 0;
- pr_debug("%p[%u]: %p: %p %Lx %Lx %Lx\n", ctx, tail, iocb, - (void __user *)(unsigned long)iocb->ki_res.obj, - iocb->ki_res.data, iocb->ki_res.res, iocb->ki_res.res2); + pr_debug("%p[%u]: %p: %Lx %Lx %Lx %Lx\n", ctx, tail, iocb, + (unsigned long long)iocb->ki_res.obj, + (unsigned long long)iocb->ki_res.data, + iocb->ki_res.res, iocb->ki_res.res2);
/* after flagging the request as done, we * must never even look at it again @@ -2049,7 +2050,7 @@ static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb, return -EFAULT; }
- req->ki_res.obj = user_ptr_addr(user_iocb); + req->ki_res.obj = (__kernel_uintptr_t)user_iocb; req->ki_res.data = iocb->aio_data; req->ki_res.res = 0; req->ki_res.res2 = 0; @@ -2080,7 +2081,7 @@ static int get_compat_iocb(struct iocb *iocb, const struct iocb __user *user_ioc struct compat_iocb compat_iocb; if (unlikely(copy_from_user(&compat_iocb, user_iocb, sizeof(struct compat_iocb)))) return -EFAULT; - iocb->aio_data = compat_iocb.aio_data; + iocb->aio_data = (__kernel_uintptr_t)compat_iocb.aio_data; iocb->aio_key = compat_iocb.aio_key; iocb->aio_rw_flags = compat_iocb.aio_rw_flags; iocb->aio_lio_opcode = compat_iocb.aio_lio_opcode; @@ -2264,7 +2265,6 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb, struct aio_kiocb *kiocb; int ret = -EINVAL; u32 key; - u64 obj = user_ptr_addr(iocb);
ctx = lookup_ioctx(ctx_id); if (unlikely(!ctx)) @@ -2283,7 +2283,7 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb, spin_lock_irq(&ctx->ctx_lock); /* TODO: use a hash or array, this sucks. */ list_for_each_entry(kiocb, &ctx->active_reqs, ki_list) { - if (kiocb->ki_res.obj == obj) { + if (user_ptr_is_same((struct iocb __user *)kiocb->ki_res.obj, iocb)) { ret = kiocb->ki_cancel(&kiocb->rw); list_del_init(&kiocb->ki_list); break; diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h index 87c270021449..edd2ac54ac42 100644 --- a/include/uapi/linux/aio_abi.h +++ b/include/uapi/linux/aio_abi.h @@ -58,10 +58,10 @@ enum {
/* read() from /dev/aio returns these structures. */ struct io_event { - __u64 data; /* the data field from the iocb */ - __u64 obj; /* what iocb this event came from */ - __s64 res; /* result code for this event */ - __s64 res2; /* secondary result */ + __kernel_uintptr_t data; /* the data field from the iocb */ + __kernel_uintptr_t obj; /* what iocb this event came from */ + __s64 res; /* result code for this event */ + __s64 res2; /* secondary result */ };
/* @@ -72,7 +72,7 @@ struct io_event {
struct iocb { /* these are internal to the kernel/libc. */ - __u64 aio_data; /* data to be returned in event's data */ + __kernel_uintptr_t aio_data; /* data to be returned in event's data */
#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN) __u32 aio_key; /* the kernel sets aio_key to the req # */