iovec_import() has a safer calling convention than import_iovec().
Signed-off-by: David Laight <[email protected]>
---
mm/process_vm_access.c | 81 ++++++++++++++++++++++--------------------
1 file changed, 42 insertions(+), 39 deletions(-)
diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index 1cc3d6f66b31..048637944d47 100644
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c
@@ -260,10 +260,10 @@ static ssize_t process_vm_rw(pid_t pid,
unsigned long riovcnt,
unsigned long flags, int vm_write)
{
- struct iovec iovstack_l[UIO_FASTIOV];
- struct iovec iovstack_r[UIO_FASTIOV];
- struct iovec *iov_l = iovstack_l;
- struct iovec *iov_r = iovstack_r;
+ struct iovec_cache cache_l;
+ struct iovec_cache cache_r;
+ struct iovec *iov_l;
+ struct iovec *iov_r;
struct iov_iter iter_l, iter_r;
ssize_t rc;
int dir = vm_write ? WRITE : READ;
@@ -272,24 +272,25 @@ static ssize_t process_vm_rw(pid_t pid,
return -EINVAL;
/* Check iovecs */
- rc = import_iovec(dir, lvec, liovcnt, UIO_FASTIOV, &iov_l, &iter_l);
- if (rc < 0)
- return rc;
- if (!iov_iter_count(&iter_l))
- goto free_iovecs;
-
- rc = import_iovec(CHECK_IOVEC_ONLY, rvec, riovcnt, UIO_FASTIOV, &iov_r,
&iter_r);
- if (rc <= 0)
- goto free_iovecs;
-
- rc = process_vm_rw_core(pid, &iter_l, iter_r.iov, iter_r.nr_segs,
- flags, vm_write);
+ iov_l = iovec_import(dir, lvec, liovcnt, &cache_l, &iter_l);
+ if (IS_ERR(iov_l))
+ return PTR_ERR(iov_l);
+ if (!iov_iter_count(&iter_l)) {
+ rc = 0;
+ goto free_iovec_l;
+ }
-free_iovecs:
- if (iov_r != iovstack_r)
+ iov_r = iovec_import(CHECK_IOVEC_ONLY, rvec, riovcnt, &cache_r,
&iter_r);
+ if (IS_ERR(iov_r)) {
+ rc = PTR_ERR(iov_r);
+ } else {
+ rc = process_vm_rw_core(pid, &iter_l, iter_r.iov,
+ iter_r.nr_segs, flags, vm_write);
kfree(iov_r);
- if (iov_l != iovstack_l)
- kfree(iov_l);
+ }
+
+free_iovec_l:
+ kfree(iov_l);
return rc;
}
@@ -319,10 +320,10 @@ compat_process_vm_rw(compat_pid_t pid,
unsigned long riovcnt,
unsigned long flags, int vm_write)
{
- struct iovec iovstack_l[UIO_FASTIOV];
- struct iovec iovstack_r[UIO_FASTIOV];
- struct iovec *iov_l = iovstack_l;
- struct iovec *iov_r = iovstack_r;
+ struct iovec_cache cache_l;
+ struct iovec_cache cache_r;
+ struct iovec *iov_l;
+ struct iovec *iov_r;
struct iov_iter iter_l, iter_r;
ssize_t rc = -EFAULT;
int dir = vm_write ? WRITE : READ;
@@ -330,23 +331,25 @@ compat_process_vm_rw(compat_pid_t pid,
if (flags != 0)
return -EINVAL;
- rc = compat_import_iovec(dir, lvec, liovcnt, UIO_FASTIOV, &iov_l,
&iter_l);
- if (rc < 0)
- return rc;
- if (!iov_iter_count(&iter_l))
- goto free_iovecs;
- rc = compat_import_iovec(0, rvec, riovcnt, UIO_FASTIOV, &iov_r,
&iter_r);
- if (rc <= 0)
- goto free_iovecs;
-
- rc = process_vm_rw_core(pid, &iter_l, iter_r.iov, iter_r.nr_segs,
- flags, vm_write);
+ iov_l = compat_iovec_import(dir, lvec, liovcnt, &cache_l, &iter_l);
+ if (IS_ERR(iov_l))
+ return PTR_ERR(iov_l);
+ if (!iov_iter_count(&iter_l)) {
+ rc = 0;
+ goto free_iovec_l;
+ }
-free_iovecs:
- if (iov_r != iovstack_r)
+ iov_r = compat_iovec_import(0, rvec, riovcnt, &cache_r, &iter_r);
+ if (IS_ERR(iov_r)) {
+ rc = PTR_ERR(iov_r);
+ } else {
+ rc = process_vm_rw_core(pid, &iter_l, iter_r.iov,
+ iter_r.nr_segs, flags, vm_write);
kfree(iov_r);
- if (iov_l != iovstack_l)
- kfree(iov_l);
+ }
+
+free_iovec_l:
+ kfree(iov_l);
return rc;
}
--
2.25.1
-
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