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authorXiubo Li <xiubli@redhat.com>2020-07-06 08:51:35 -0400
committerIlya Dryomov <idryomov@gmail.com>2020-08-03 11:05:25 +0200
commitd1d9655052606fd9078e896668ec90191372d513 (patch)
treedcdb21734df1009fd848b91d7d3d54fbd57387b0 /fs/ceph/file.c
parentceph: clean up and optimize ceph_check_delayed_caps() (diff)
downloadlinux-dev-d1d9655052606fd9078e896668ec90191372d513.tar.xz
linux-dev-d1d9655052606fd9078e896668ec90191372d513.zip
ceph: do not access the kiocb after aio requests
In aio case, if the completion comes very fast just before the ceph_read_iter() returns to fs/aio.c, the kiocb will be freed in the completion callback, then if ceph_read_iter() access again we will potentially hit the use-after-free bug. [ jlayton: initialize direct_lock early, and use it everywhere ] URL: https://tracker.ceph.com/issues/45649 Signed-off-by: Xiubo Li <xiubli@redhat.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs/ceph/file.c')
-rw-r--r--fs/ceph/file.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 160644ddaeed..d51c3f2fdca0 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -1538,6 +1538,7 @@ static ssize_t ceph_read_iter(struct kiocb *iocb, struct iov_iter *to)
struct inode *inode = file_inode(filp);
struct ceph_inode_info *ci = ceph_inode(inode);
struct page *pinned_page = NULL;
+ bool direct_lock = iocb->ki_flags & IOCB_DIRECT;
ssize_t ret;
int want, got = 0;
int retry_op = 0, read = 0;
@@ -1546,7 +1547,7 @@ again:
dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len, inode);
- if (iocb->ki_flags & IOCB_DIRECT)
+ if (direct_lock)
ceph_start_io_direct(inode);
else
ceph_start_io_read(inode);
@@ -1603,7 +1604,7 @@ again:
}
ceph_put_cap_refs(ci, got);
- if (iocb->ki_flags & IOCB_DIRECT)
+ if (direct_lock)
ceph_end_io_direct(inode);
else
ceph_end_io_read(inode);