fs/nfsd/filecache.c:1118 nfsd_file_do_acquire() warn: passing freed memory 'nf'
From: Dan Carpenter
Date: Sat Nov 05 2022 - 07:17:55 EST
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: b208b9fbbcba743fb269d15cb46a4036b01936b1
commit: 243a5263014a30436c93ed3f1f864c1da845455e nfsd: rework hashtable handling in nfsd_do_file_acquire
config: alpha-randconfig-m041-20221030
compiler: alpha-linux-gcc (GCC) 12.1.0
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Reported-by: Dan Carpenter <error27@xxxxxxxxx>
smatch warnings:
fs/nfsd/filecache.c:1118 nfsd_file_do_acquire() warn: passing freed memory 'nf'
vim +/nf +1118 fs/nfsd/filecache.c
fb70bf124b051d Chuck Lever 2022-03-30 1036 static __be32
be0230069fcbf7 Chuck Lever 2022-07-08 1037 nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
fb70bf124b051d Chuck Lever 2022-03-30 1038 unsigned int may_flags, struct nfsd_file **pnf, bool open)
65294c1f2c5e72 Jeff Layton 2019-08-18 1039 {
ce502f81ba884c Chuck Lever 2022-07-08 1040 struct nfsd_file_lookup_key key = {
ce502f81ba884c Chuck Lever 2022-07-08 1041 .type = NFSD_FILE_KEY_FULL,
ce502f81ba884c Chuck Lever 2022-07-08 1042 .need = may_flags & NFSD_FILE_MAY_MASK,
ce502f81ba884c Chuck Lever 2022-07-08 1043 .net = SVC_NET(rqstp),
ce502f81ba884c Chuck Lever 2022-07-08 1044 };
243a5263014a30 Jeff Layton 2022-10-04 1045 bool open_retry = true;
243a5263014a30 Jeff Layton 2022-10-04 1046 struct nfsd_file *nf;
ce502f81ba884c Chuck Lever 2022-07-08 1047 __be32 status;
243a5263014a30 Jeff Layton 2022-10-04 1048 int ret;
65294c1f2c5e72 Jeff Layton 2019-08-18 1049
65294c1f2c5e72 Jeff Layton 2019-08-18 1050 status = fh_verify(rqstp, fhp, S_IFREG,
65294c1f2c5e72 Jeff Layton 2019-08-18 1051 may_flags|NFSD_MAY_OWNER_OVERRIDE);
65294c1f2c5e72 Jeff Layton 2019-08-18 1052 if (status != nfs_ok)
65294c1f2c5e72 Jeff Layton 2019-08-18 1053 return status;
ce502f81ba884c Chuck Lever 2022-07-08 1054 key.inode = d_inode(fhp->fh_dentry);
ce502f81ba884c Chuck Lever 2022-07-08 1055 key.cred = get_current_cred();
65294c1f2c5e72 Jeff Layton 2019-08-18 1056
65294c1f2c5e72 Jeff Layton 2019-08-18 1057 retry:
243a5263014a30 Jeff Layton 2022-10-04 1058 rcu_read_lock();
243a5263014a30 Jeff Layton 2022-10-04 1059 nf = rhashtable_lookup(&nfsd_file_rhash_tbl, &key,
ce502f81ba884c Chuck Lever 2022-07-08 1060 nfsd_file_rhash_params);
ce502f81ba884c Chuck Lever 2022-07-08 1061 if (nf)
ce502f81ba884c Chuck Lever 2022-07-08 1062 nf = nfsd_file_get(nf);
243a5263014a30 Jeff Layton 2022-10-04 1063 rcu_read_unlock();
65294c1f2c5e72 Jeff Layton 2019-08-18 1064 if (nf)
65294c1f2c5e72 Jeff Layton 2019-08-18 1065 goto wait_for_construction;
65294c1f2c5e72 Jeff Layton 2019-08-18 1066
243a5263014a30 Jeff Layton 2022-10-04 1067 nf = nfsd_file_alloc(&key, may_flags);
243a5263014a30 Jeff Layton 2022-10-04 1068 if (!nf) {
54f7df7094b329 Chuck Lever 2022-07-08 1069 status = nfserr_jukebox;
54f7df7094b329 Chuck Lever 2022-07-08 1070 goto out_status;
65294c1f2c5e72 Jeff Layton 2019-08-18 1071 }
65294c1f2c5e72 Jeff Layton 2019-08-18 1072
243a5263014a30 Jeff Layton 2022-10-04 1073 ret = rhashtable_lookup_insert_key(&nfsd_file_rhash_tbl,
243a5263014a30 Jeff Layton 2022-10-04 1074 &key, &nf->nf_rhash,
ce502f81ba884c Chuck Lever 2022-07-08 1075 nfsd_file_rhash_params);
243a5263014a30 Jeff Layton 2022-10-04 1076 if (likely(ret == 0))
65294c1f2c5e72 Jeff Layton 2019-08-18 1077 goto open_file;
243a5263014a30 Jeff Layton 2022-10-04 1078
243a5263014a30 Jeff Layton 2022-10-04 1079 nfsd_file_slab_free(&nf->nf_rcu);
243a5263014a30 Jeff Layton 2022-10-04 1080 if (ret == -EEXIST)
243a5263014a30 Jeff Layton 2022-10-04 1081 goto retry;
243a5263014a30 Jeff Layton 2022-10-04 1082 trace_nfsd_file_insert_err(rqstp, key.inode, may_flags, ret);
243a5263014a30 Jeff Layton 2022-10-04 1083 status = nfserr_jukebox;
243a5263014a30 Jeff Layton 2022-10-04 1084 goto out_status;
65294c1f2c5e72 Jeff Layton 2019-08-18 1085
65294c1f2c5e72 Jeff Layton 2019-08-18 1086 wait_for_construction:
65294c1f2c5e72 Jeff Layton 2019-08-18 1087 wait_on_bit(&nf->nf_flags, NFSD_FILE_PENDING, TASK_UNINTERRUPTIBLE);
65294c1f2c5e72 Jeff Layton 2019-08-18 1088
65294c1f2c5e72 Jeff Layton 2019-08-18 1089 /* Did construction of this file fail? */
65294c1f2c5e72 Jeff Layton 2019-08-18 1090 if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
ce502f81ba884c Chuck Lever 2022-07-08 1091 trace_nfsd_file_cons_err(rqstp, key.inode, may_flags, nf);
243a5263014a30 Jeff Layton 2022-10-04 1092 if (!open_retry) {
28c7d86bb6172f Trond Myklebust 2020-01-06 1093 status = nfserr_jukebox;
28c7d86bb6172f Trond Myklebust 2020-01-06 1094 goto out;
28c7d86bb6172f Trond Myklebust 2020-01-06 1095 }
243a5263014a30 Jeff Layton 2022-10-04 1096 open_retry = false;
65294c1f2c5e72 Jeff Layton 2019-08-18 1097 nfsd_file_put_noref(nf);
65294c1f2c5e72 Jeff Layton 2019-08-18 1098 goto retry;
65294c1f2c5e72 Jeff Layton 2019-08-18 1099 }
65294c1f2c5e72 Jeff Layton 2019-08-18 1100
4a0e73e635e3f3 Chuck Lever 2022-07-08 1101 nfsd_file_lru_remove(nf);
65294c1f2c5e72 Jeff Layton 2019-08-18 1102 this_cpu_inc(nfsd_file_cache_hits);
65294c1f2c5e72 Jeff Layton 2019-08-18 1103
23ba98de6dcec6 Jeff Layton 2022-07-29 1104 status = nfserrno(nfsd_open_break_lease(file_inode(nf->nf_file), may_flags));
65294c1f2c5e72 Jeff Layton 2019-08-18 1105 out:
65294c1f2c5e72 Jeff Layton 2019-08-18 1106 if (status == nfs_ok) {
29d4bdbbb910f3 Chuck Lever 2022-07-08 1107 if (open)
29d4bdbbb910f3 Chuck Lever 2022-07-08 1108 this_cpu_inc(nfsd_file_acquisitions);
65294c1f2c5e72 Jeff Layton 2019-08-18 1109 *pnf = nf;
65294c1f2c5e72 Jeff Layton 2019-08-18 1110 } else {
65294c1f2c5e72 Jeff Layton 2019-08-18 1111 nfsd_file_put(nf);
65294c1f2c5e72 Jeff Layton 2019-08-18 1112 nf = NULL;
65294c1f2c5e72 Jeff Layton 2019-08-18 1113 }
65294c1f2c5e72 Jeff Layton 2019-08-18 1114
54f7df7094b329 Chuck Lever 2022-07-08 1115 out_status:
ce502f81ba884c Chuck Lever 2022-07-08 1116 put_cred(key.cred);
be0230069fcbf7 Chuck Lever 2022-07-08 1117 if (open)
ce502f81ba884c Chuck Lever 2022-07-08 @1118 trace_nfsd_file_acquire(rqstp, key.inode, may_flags, nf, status);
Passing freed pointers to the trace code is a border line case... Not
sure if we care.
65294c1f2c5e72 Jeff Layton 2019-08-18 1119 return status;
65294c1f2c5e72 Jeff Layton 2019-08-18 1120
65294c1f2c5e72 Jeff Layton 2019-08-18 1121 open_file:
b40a2839470cd6 Chuck Lever 2022-07-08 1122 trace_nfsd_file_alloc(nf);
427f5f83a3191c Chuck Lever 2022-07-08 1123 nf->nf_mark = nfsd_file_mark_find_or_create(nf, key.inode);
fb70bf124b051d Chuck Lever 2022-03-30 1124 if (nf->nf_mark) {
0122e882119ddb Chuck Lever 2022-03-27 1125 if (open) {
f4d84c52643ae1 Chuck Lever 2022-03-27 1126 status = nfsd_open_verified(rqstp, fhp, may_flags,
f4d84c52643ae1 Chuck Lever 2022-03-27 1127 &nf->nf_file);
0122e882119ddb Chuck Lever 2022-03-27 1128 trace_nfsd_file_open(nf, status);
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