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ext4: fix possible use-after-free with AIO

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Running AIO is pinning inode in memory using file reference. Once AIO
is completed using aio_complete(), file reference is put and inode can
be freed from memory. So we have to be sure that calling aio_complete()
is the last thing we do with the inode.

CC: stable@vger.kernel.org
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Jan Kara
2013-01-29 22:48:17 -05:00
committed by Theodore Ts'o
parent b1deefc99e
commit 091e26dfc1
2 changed files with 5 additions and 6 deletions
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2
fs/ext4/inode.c
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@@ -2850,9 +2850,9 @@ static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) { if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
ext4_free_io_end(io_end); ext4_free_io_end(io_end);
out: out:
inode_dio_done(inode);
if (is_async) if (is_async)
aio_complete(iocb, ret, 0); aio_complete(iocb, ret, 0);
inode_dio_done(inode);
return; return;
} }

9
fs/ext4/page-io.c
View File

@@ -102,14 +102,13 @@ static int ext4_end_io(ext4_io_end_t *io)
"(inode %lu, offset %llu, size %zd, error %d)", "(inode %lu, offset %llu, size %zd, error %d)",
inode->i_ino, offset, size, ret); inode->i_ino, offset, size, ret);
} }
if (io->iocb)
aio_complete(io->iocb, io->result, 0);
if (io->flag & EXT4_IO_END_DIRECT)
inode_dio_done(inode);
/* Wake up anyone waiting on unwritten extent conversion */ /* Wake up anyone waiting on unwritten extent conversion */
if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten)) if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten))
wake_up_all(ext4_ioend_wq(inode)); wake_up_all(ext4_ioend_wq(inode));
if (io->flag & EXT4_IO_END_DIRECT)
inode_dio_done(inode);
if (io->iocb)
aio_complete(io->iocb, io->result, 0);
return ret; return ret;
} }