NFS: Don't use GFP_KERNEL in rpcsec_gss downcalls

Again, we can deadlock if the memory reclaim triggers a writeback that
requires a rpcsec_gss credential lookup.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

6 files changed, 32 insertions, 27 deletions

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 6654c8534d32..48a7939dc9e2 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -229,7 +229,7 @@ gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct
                 p = ERR_PTR(-EFAULT);
                 goto err;
         }
-        ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx);
+        ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, GFP_NOFS);
         if (ret < 0) {
                 p = ERR_PTR(ret);
                 goto err;
diff --git a/net/sunrpc/auth_gss/gss_krb5_keys.c b/net/sunrpc/auth_gss/gss_krb5_keys.c
index 33b87f04b30b..76e42e6be755 100644
--- a/net/sunrpc/auth_gss/gss_krb5_keys.c
+++ b/net/sunrpc/auth_gss/gss_krb5_keys.c
@@ -150,7 +150,8 @@ static void krb5_nfold(u32 inbits, const u8 *in,
 u32 krb5_derive_key(const struct gss_krb5_enctype *gk5e,
                     const struct xdr_netobj *inkey,
                     struct xdr_netobj *outkey,
-                    const struct xdr_netobj *in_constant)
+                    const struct xdr_netobj *in_constant,
+                    gfp_t gfp_mask)
 {
         size_t blocksize, keybytes, keylength, n;
         unsigned char *inblockdata, *outblockdata, *rawkey;
@@ -175,15 +176,15 @@ u32 krb5_derive_key(const struct gss_krb5_enctype *gk5e,
         /* allocate and set up buffers */
 
         ret = ENOMEM;
-        inblockdata = kmalloc(blocksize, GFP_KERNEL);
+        inblockdata = kmalloc(blocksize, gfp_mask);
         if (inblockdata == NULL)
                 goto err_free_cipher;
 
-        outblockdata = kmalloc(blocksize, GFP_KERNEL);
+        outblockdata = kmalloc(blocksize, gfp_mask);
         if (outblockdata == NULL)
                 goto err_free_in;
 
-        rawkey = kmalloc(keybytes, GFP_KERNEL);
+        rawkey = kmalloc(keybytes, gfp_mask);
         if (rawkey == NULL)
                 goto err_free_out;
 
diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c
index 7c249a3f9a03..032644610524 100644
--- a/net/sunrpc/auth_gss/gss_krb5_mech.c
+++ b/net/sunrpc/auth_gss/gss_krb5_mech.c
@@ -369,7 +369,7 @@ set_cdata(u8 cdata[GSS_KRB5_K5CLENGTH], u32 usage, u8 seed)
 }
 
 static int
-context_derive_keys_des3(struct krb5_ctx *ctx)
+context_derive_keys_des3(struct krb5_ctx *ctx, gfp_t gfp_mask)
 {
         struct xdr_netobj c, keyin, keyout;
         u8 cdata[GSS_KRB5_K5CLENGTH];
@@ -396,7 +396,7 @@ context_derive_keys_des3(struct krb5_ctx *ctx)
         /* derive cksum */
         set_cdata(cdata, KG_USAGE_SIGN, KEY_USAGE_SEED_CHECKSUM);
         keyout.data = ctx->cksum;
-        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
+        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
         if (err) {
                 dprintk("%s: Error %d deriving cksum key\n",
                         __func__, err);
@@ -487,7 +487,7 @@ out_err:
 }
 
 static int
-context_derive_keys_new(struct krb5_ctx *ctx)
+context_derive_keys_new(struct krb5_ctx *ctx, gfp_t gfp_mask)
 {
         struct xdr_netobj c, keyin, keyout;
         u8 cdata[GSS_KRB5_K5CLENGTH];
@@ -503,7 +503,7 @@ context_derive_keys_new(struct krb5_ctx *ctx)
         /* initiator seal encryption */
         set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
         keyout.data = ctx->initiator_seal;
-        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
+        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
         if (err) {
                 dprintk("%s: Error %d deriving initiator_seal key\n",
                         __func__, err);
@@ -518,7 +518,7 @@ context_derive_keys_new(struct krb5_ctx *ctx)
         /* acceptor seal encryption */
         set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_ENCRYPTION);
         keyout.data = ctx->acceptor_seal;
-        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
+        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
         if (err) {
                 dprintk("%s: Error %d deriving acceptor_seal key\n",
                         __func__, err);
@@ -533,7 +533,7 @@ context_derive_keys_new(struct krb5_ctx *ctx)
         /* initiator sign checksum */
         set_cdata(cdata, KG_USAGE_INITIATOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
         keyout.data = ctx->initiator_sign;
-        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
+        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
         if (err) {
                 dprintk("%s: Error %d deriving initiator_sign key\n",
                         __func__, err);
@@ -543,7 +543,7 @@ context_derive_keys_new(struct krb5_ctx *ctx)
         /* acceptor sign checksum */
         set_cdata(cdata, KG_USAGE_ACCEPTOR_SIGN, KEY_USAGE_SEED_CHECKSUM);
         keyout.data = ctx->acceptor_sign;
-        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
+        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
         if (err) {
                 dprintk("%s: Error %d deriving acceptor_sign key\n",
                         __func__, err);
@@ -553,7 +553,7 @@ context_derive_keys_new(struct krb5_ctx *ctx)
         /* initiator seal integrity */
         set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
         keyout.data = ctx->initiator_integ;
-        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
+        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
         if (err) {
                 dprintk("%s: Error %d deriving initiator_integ key\n",
                         __func__, err);
@@ -563,7 +563,7 @@ context_derive_keys_new(struct krb5_ctx *ctx)
         /* acceptor seal integrity */
         set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
         keyout.data = ctx->acceptor_integ;
-        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c);
+        err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
         if (err) {
                 dprintk("%s: Error %d deriving acceptor_integ key\n",
                         __func__, err);
@@ -598,7 +598,8 @@ out_err:
 }
 
 static int
-gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx)
+gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx,
+                gfp_t gfp_mask)
 {
         int keylen;
 
@@ -645,7 +646,7 @@ gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx)
         }
 
         ctx->mech_used.data = kmemdup(gss_kerberos_mech.gm_oid.data,
-                                      gss_kerberos_mech.gm_oid.len, GFP_KERNEL);
+                                      gss_kerberos_mech.gm_oid.len, gfp_mask);
         if (unlikely(ctx->mech_used.data == NULL)) {
                 p = ERR_PTR(-ENOMEM);
                 goto out_err;
@@ -654,12 +655,12 @@ gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx)
 
         switch (ctx->enctype) {
         case ENCTYPE_DES3_CBC_RAW:
-                return context_derive_keys_des3(ctx);
+                return context_derive_keys_des3(ctx, gfp_mask);
         case ENCTYPE_ARCFOUR_HMAC:
                 return context_derive_keys_rc4(ctx);
         case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
         case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
-                return context_derive_keys_new(ctx);
+                return context_derive_keys_new(ctx, gfp_mask);
         default:
                 return -EINVAL;
         }
@@ -670,20 +671,21 @@ out_err:
 
 static int
 gss_import_sec_context_kerberos(const void *p, size_t len,
-                                struct gss_ctx *ctx_id)
+                                struct gss_ctx *ctx_id,
+                                gfp_t gfp_mask)
 {
         const void *end = (const void *)((const char *)p + len);
         struct  krb5_ctx *ctx;
         int ret;
 
-        ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+        ctx = kzalloc(sizeof(*ctx), gfp_mask);
         if (ctx == NULL)
                 return -ENOMEM;
 
         if (len == 85)
                 ret = gss_import_v1_context(p, end, ctx);
         else
-                ret = gss_import_v2_context(p, end, ctx);
+                ret = gss_import_v2_context(p, end, ctx, gfp_mask);
 
         if (ret == 0)
                 ctx_id->internal_ctx_id = ctx;
diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c b/net/sunrpc/auth_gss/gss_mech_switch.c
index 28a84ef41d13..2689de39dc78 100644
--- a/net/sunrpc/auth_gss/gss_mech_switch.c
+++ b/net/sunrpc/auth_gss/gss_mech_switch.c
@@ -249,14 +249,15 @@ EXPORT_SYMBOL_GPL(gss_mech_put);
 int
 gss_import_sec_context(const void *input_token, size_t bufsize,
                        struct gss_api_mech      *mech,
-                       struct gss_ctx           **ctx_id)
+                       struct gss_ctx           **ctx_id,
+                       gfp_t gfp_mask)
 {
-        if (!(*ctx_id = kzalloc(sizeof(**ctx_id), GFP_KERNEL)))
+        if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
                 return -ENOMEM;
         (*ctx_id)->mech_type = gss_mech_get(mech);
 
         return mech->gm_ops
-                ->gss_import_sec_context(input_token, bufsize, *ctx_id);
+                ->gss_import_sec_context(input_token, bufsize, *ctx_id, gfp_mask);
 }
 
 /* gss_get_mic: compute a mic over message and return mic_token. */
diff --git a/net/sunrpc/auth_gss/gss_spkm3_mech.c b/net/sunrpc/auth_gss/gss_spkm3_mech.c
index 035e1dd6af1b..dc3f1f5ed865 100644
--- a/net/sunrpc/auth_gss/gss_spkm3_mech.c
+++ b/net/sunrpc/auth_gss/gss_spkm3_mech.c
@@ -84,13 +84,14 @@ simple_get_netobj(const void *p, const void *end, struct xdr_netobj *res)
 
 static int
 gss_import_sec_context_spkm3(const void *p, size_t len,
-                                struct gss_ctx *ctx_id)
+                                struct gss_ctx *ctx_id,
+                                gfp_t gfp_mask)
 {
         const void *end = (const void *)((const char *)p + len);
         struct  spkm3_ctx *ctx;
         int     version;
 
-        if (!(ctx = kzalloc(sizeof(*ctx), GFP_NOFS)))
+        if (!(ctx = kzalloc(sizeof(*ctx), gfp_mask)))
                 goto out_err;
 
         p = simple_get_bytes(p, end, &version, sizeof(version));
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 1d9ac4ac818a..cc385b3a59c2 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -494,7 +494,7 @@ static int rsc_parse(struct cache_detail *cd,
                 len = qword_get(&mesg, buf, mlen);
                 if (len < 0)
                         goto out;
-                status = gss_import_sec_context(buf, len, gm, &rsci.mechctx);
+                status = gss_import_sec_context(buf, len, gm, &rsci.mechctx, GFP_KERNEL);
                 if (status)
                         goto out;