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NFSD: fix use-after-free in __nfs42_ssc_open()

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[ Upstream commit 75333d48f92256a0dec91dbf07835e804fc411c0 ]

Problem caused by source's vfsmount being unmounted but remains
on the delayed unmount list. This happens when nfs42_ssc_open()
return errors.

Fixed by removing nfsd4_interssc_connect(), leave the vfsmount
for the laundromat to unmount when idle time expires.

We don't need to call nfs_do_sb_deactive when nfs42_ssc_open
return errors since the file was not opened so nfs_server->active
was not incremented. Same as in nfsd4_copy, if we fail to
launch nfsd4_do_async_copy thread then there's no need to
call nfs_do_sb_deactive

Reported-by: Xingyuan Mo <hdthky0@gmail.com>
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Tested-by: Xingyuan Mo <hdthky0@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Dai Ngo 2022-12-12 14:50:11 -08:00 committed by Greg Kroah-Hartman
parent ba50fee6b4
commit 650b69b17c
1 changed files with 5 additions and 15 deletions
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20
fs/nfsd/nfs4proc.c
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@ -1465,13 +1465,6 @@ out_err:
return status;
}
static void
nfsd4_interssc_disconnect(struct vfsmount *ss_mnt)
{
nfs_do_sb_deactive(ss_mnt->mnt_sb);
mntput(ss_mnt);
}
/*
* Verify COPY destination stateid.
*
@ -1574,11 +1567,6 @@ nfsd4_cleanup_inter_ssc(struct vfsmount *ss_mnt, struct file *filp,
{
}
static void
nfsd4_interssc_disconnect(struct vfsmount *ss_mnt)
{
}
static struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
struct nfs_fh *src_fh,
nfs4_stateid *stateid)
@ -1774,7 +1762,7 @@ static int nfsd4_do_async_copy(void *data)
default:
nfserr = nfserr_offload_denied;
}
nfsd4_interssc_disconnect(copy->ss_mnt);
/* ss_mnt will be unmounted by the laundromat */
goto do_callback;
}
nfserr = nfsd4_do_copy(copy, filp, copy->nf_dst->nf_file,
@ -1855,8 +1843,10 @@ out_err:
if (async_copy)
cleanup_async_copy(async_copy);
status = nfserrno(-ENOMEM);
if (nfsd4_ssc_is_inter(copy))
nfsd4_interssc_disconnect(copy->ss_mnt);
/*
* source's vfsmount of inter-copy will be unmounted
* by the laundromat
*/
goto out;
}