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NFSD: Fix nfs4_verifier memory alignment
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Clean up due to code review.

The nfs4_verifier's data field is not guaranteed to be u32-aligned.
Casting an array of chars to a u32 * is considered generally
hazardous.

We can fix most of this by using a __be32 array to generate the
verifier's contents and then byte-copying it into the verifier field.

However, there is one spot where there is a backwards compatibility
constraint: the do_nfsd_create() call expects a verifier which is
32-bit aligned.  Fix this spot by forcing the alignment of the create
verifier in the nfsd4_open args structure.

Also, sizeof(nfs4_verifer) is the size of the in-core verifier data
structure, but NFS4_VERIFIER_SIZE is the number of octets in an XDR'd
verifier.  The two are not interchangeable, even if they happen to
have the same value.

Signed-off-by: Chuck Lever <[email protected]>
Signed-off-by: J. Bruce Fields <[email protected]>
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@chucklever
chucklever authored and J. Bruce Fields committed Mar 20, 2012
1 parent 8f199b8 commit ab4684d
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Showing 4 changed files with 31 additions and 28 deletions.
19 changes: 11 additions & 8 deletions fs/nfsd/nfs4proc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -489,14 +489,20 @@ nfsd4_access(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
&access->ac_supported);
}

static void gen_boot_verifier(nfs4_verifier *verifier)
{
__be32 verf[2];

verf[0] = (__be32)nfssvc_boot.tv_sec;
verf[1] = (__be32)nfssvc_boot.tv_usec;
memcpy(verifier->data, verf, sizeof(verifier->data));
}

static __be32
nfsd4_commit(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
struct nfsd4_commit *commit)
{
u32 *p = (u32 *)commit->co_verf.data;
*p++ = nfssvc_boot.tv_sec;
*p++ = nfssvc_boot.tv_usec;

gen_boot_verifier(&commit->co_verf);
return nfsd_commit(rqstp, &cstate->current_fh, commit->co_offset,
commit->co_count);
}
Expand Down Expand Up @@ -873,7 +879,6 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
{
stateid_t *stateid = &write->wr_stateid;
struct file *filp = NULL;
u32 *p;
__be32 status = nfs_ok;
unsigned long cnt;

Expand All @@ -895,9 +900,7 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,

cnt = write->wr_buflen;
write->wr_how_written = write->wr_stable_how;
p = (u32 *)write->wr_verifier.data;
*p++ = nfssvc_boot.tv_sec;
*p++ = nfssvc_boot.tv_usec;
gen_boot_verifier(&write->wr_verifier);

status = nfsd_write(rqstp, &cstate->current_fh, filp,
write->wr_offset, rqstp->rq_vec, write->wr_vlen,
Expand Down
8 changes: 4 additions & 4 deletions fs/nfsd/nfs4state.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1174,12 +1174,12 @@ static void gen_clid(struct nfs4_client *clp)

static void gen_confirm(struct nfs4_client *clp)
{
__be32 verf[2];
static u32 i;
u32 *p;

p = (u32 *)clp->cl_confirm.data;
*p++ = get_seconds();
*p++ = i++;
verf[0] = (__be32)get_seconds();
verf[1] = (__be32)i++;
memcpy(clp->cl_confirm.data, verf, sizeof(clp->cl_confirm.data));
}

static struct nfs4_stid *find_stateid(struct nfs4_client *cl, stateid_t *t)
Expand Down
28 changes: 14 additions & 14 deletions fs/nfsd/nfs4xdr.c
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Original file line number Diff line number Diff line change
Expand Up @@ -749,14 +749,14 @@ nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
goto out;
break;
case NFS4_CREATE_EXCLUSIVE:
READ_BUF(8);
COPYMEM(open->op_verf.data, 8);
READ_BUF(NFS4_VERIFIER_SIZE);
COPYMEM(open->op_verf.data, NFS4_VERIFIER_SIZE);
break;
case NFS4_CREATE_EXCLUSIVE4_1:
if (argp->minorversion < 1)
goto xdr_error;
READ_BUF(8);
COPYMEM(open->op_verf.data, 8);
READ_BUF(NFS4_VERIFIER_SIZE);
COPYMEM(open->op_verf.data, NFS4_VERIFIER_SIZE);
status = nfsd4_decode_fattr(argp, open->op_bmval,
&open->op_iattr, &open->op_acl);
if (status)
Expand Down Expand Up @@ -989,8 +989,8 @@ nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, struct nfsd4_setclient
{
DECODE_HEAD;

READ_BUF(8);
COPYMEM(setclientid->se_verf.data, 8);
READ_BUF(NFS4_VERIFIER_SIZE);
COPYMEM(setclientid->se_verf.data, NFS4_VERIFIER_SIZE);

status = nfsd4_decode_opaque(argp, &setclientid->se_name);
if (status)
Expand All @@ -1015,9 +1015,9 @@ nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_s
{
DECODE_HEAD;

READ_BUF(8 + sizeof(nfs4_verifier));
READ_BUF(8 + NFS4_VERIFIER_SIZE);
COPYMEM(&scd_c->sc_clientid, 8);
COPYMEM(&scd_c->sc_confirm, sizeof(nfs4_verifier));
COPYMEM(&scd_c->sc_confirm, NFS4_VERIFIER_SIZE);

DECODE_TAIL;
}
Expand Down Expand Up @@ -2659,8 +2659,8 @@ nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_
__be32 *p;

if (!nfserr) {
RESERVE_SPACE(8);
WRITEMEM(commit->co_verf.data, 8);
RESERVE_SPACE(NFS4_VERIFIER_SIZE);
WRITEMEM(commit->co_verf.data, NFS4_VERIFIER_SIZE);
ADJUST_ARGS();
}
return nfserr;
Expand Down Expand Up @@ -3020,7 +3020,7 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4
if (resp->xbuf->page_len)
return nfserr_resource;

RESERVE_SPACE(8); /* verifier */
RESERVE_SPACE(NFS4_VERIFIER_SIZE);
savep = p;

/* XXX: Following NFSv3, we ignore the READDIR verifier for now. */
Expand Down Expand Up @@ -3221,9 +3221,9 @@ nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, __be32 nfserr, struct n
__be32 *p;

if (!nfserr) {
RESERVE_SPACE(8 + sizeof(nfs4_verifier));
RESERVE_SPACE(8 + NFS4_VERIFIER_SIZE);
WRITEMEM(&scd->se_clientid, 8);
WRITEMEM(&scd->se_confirm, sizeof(nfs4_verifier));
WRITEMEM(&scd->se_confirm, NFS4_VERIFIER_SIZE);
ADJUST_ARGS();
}
else if (nfserr == nfserr_clid_inuse) {
Expand All @@ -3244,7 +3244,7 @@ nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_w
RESERVE_SPACE(16);
WRITE32(write->wr_bytes_written);
WRITE32(write->wr_how_written);
WRITEMEM(write->wr_verifier.data, 8);
WRITEMEM(write->wr_verifier.data, NFS4_VERIFIER_SIZE);
ADJUST_ARGS();
}
return nfserr;
Expand Down
4 changes: 2 additions & 2 deletions fs/nfsd/xdr4.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -228,7 +228,8 @@ struct nfsd4_open {
u32 op_createmode; /* request */
u32 op_bmval[3]; /* request */
struct iattr iattr; /* UNCHECKED4, GUARDED4, EXCLUSIVE4_1 */
nfs4_verifier verf; /* EXCLUSIVE4 */
nfs4_verifier op_verf __attribute__((aligned(32)));
/* EXCLUSIVE4 */
clientid_t op_clientid; /* request */
struct xdr_netobj op_owner; /* request */
u32 op_seqid; /* request */
Expand All @@ -247,7 +248,6 @@ struct nfsd4_open {
struct nfs4_acl *op_acl;
};
#define op_iattr iattr
#define op_verf verf

struct nfsd4_open_confirm {
stateid_t oc_req_stateid /* request */;
Expand Down

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