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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-21 16:06:20 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-21 16:06:20 -0700
commita70b52ec1aaeaf60f4739edb1b422827cb6f3893 (patch)
treeb85acd421b97f018400bc55cb8eb14b4468c3b73 /fs/aio.c
parentff8ce5f67ddca709fe59e6173f89260f0fdc2b22 (diff)
downloadlwn-a70b52ec1aaeaf60f4739edb1b422827cb6f3893.tar.gz
lwn-a70b52ec1aaeaf60f4739edb1b422827cb6f3893.zip
vfs: make AIO use the proper rw_verify_area() area helpers
We had for some reason overlooked the AIO interface, and it didn't use the proper rw_verify_area() helper function that checks (for example) mandatory locking on the file, and that the size of the access doesn't cause us to overflow the provided offset limits etc. Instead, AIO did just the security_file_permission() thing (that rw_verify_area() also does) directly. This fixes it to do all the proper helper functions, which not only means that now mandatory file locking works with AIO too, we can actually remove lines of code. Reported-by: Manish Honap <manish_honap_vit@yahoo.co.in> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/aio.c')
-rw-r--r--fs/aio.c30
1 files changed, 14 insertions, 16 deletions
diff --git a/fs/aio.c b/fs/aio.c
index 67a6db3e1b6f..e7f2fad7b4ce 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1456,6 +1456,10 @@ static ssize_t aio_setup_vectored_rw(int type, struct kiocb *kiocb, bool compat)
if (ret < 0)
goto out;
+ ret = rw_verify_area(type, kiocb->ki_filp, &kiocb->ki_pos, ret);
+ if (ret < 0)
+ goto out;
+
kiocb->ki_nr_segs = kiocb->ki_nbytes;
kiocb->ki_cur_seg = 0;
/* ki_nbytes/left now reflect bytes instead of segs */
@@ -1467,11 +1471,17 @@ out:
return ret;
}
-static ssize_t aio_setup_single_vector(struct kiocb *kiocb)
+static ssize_t aio_setup_single_vector(int type, struct file * file, struct kiocb *kiocb)
{
+ int bytes;
+
+ bytes = rw_verify_area(type, file, &kiocb->ki_pos, kiocb->ki_left);
+ if (bytes < 0)
+ return bytes;
+
kiocb->ki_iovec = &kiocb->ki_inline_vec;
kiocb->ki_iovec->iov_base = kiocb->ki_buf;
- kiocb->ki_iovec->iov_len = kiocb->ki_left;
+ kiocb->ki_iovec->iov_len = bytes;
kiocb->ki_nr_segs = 1;
kiocb->ki_cur_seg = 0;
return 0;
@@ -1496,10 +1506,7 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
if (unlikely(!access_ok(VERIFY_WRITE, kiocb->ki_buf,
kiocb->ki_left)))
break;
- ret = security_file_permission(file, MAY_READ);
- if (unlikely(ret))
- break;
- ret = aio_setup_single_vector(kiocb);
+ ret = aio_setup_single_vector(READ, file, kiocb);
if (ret)
break;
ret = -EINVAL;
@@ -1514,10 +1521,7 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
if (unlikely(!access_ok(VERIFY_READ, kiocb->ki_buf,
kiocb->ki_left)))
break;
- ret = security_file_permission(file, MAY_WRITE);
- if (unlikely(ret))
- break;
- ret = aio_setup_single_vector(kiocb);
+ ret = aio_setup_single_vector(WRITE, file, kiocb);
if (ret)
break;
ret = -EINVAL;
@@ -1528,9 +1532,6 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
ret = -EBADF;
if (unlikely(!(file->f_mode & FMODE_READ)))
break;
- ret = security_file_permission(file, MAY_READ);
- if (unlikely(ret))
- break;
ret = aio_setup_vectored_rw(READ, kiocb, compat);
if (ret)
break;
@@ -1542,9 +1543,6 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
ret = -EBADF;
if (unlikely(!(file->f_mode & FMODE_WRITE)))
break;
- ret = security_file_permission(file, MAY_WRITE);
- if (unlikely(ret))
- break;
ret = aio_setup_vectored_rw(WRITE, kiocb, compat);
if (ret)
break;