From c3ed222745d9ad7b69299b349a64ba533c64a34f Mon Sep 17 00:00:00 2001 From: Benjamin Coddington Date: Sat, 14 May 2022 07:05:13 -0400 Subject: [PATCH] NFSv4: Fix free of uninitialized nfs4_label on referral lookup. Send along the already-allocated fattr along with nfs4_fs_locations, and drop the memcpy of fattr. We end up growing two more allocations, but this fixes up a crash as: PID: 790 TASK: ffff88811b43c000 CPU: 0 COMMAND: "ls" #0 [ffffc90000857920] panic at ffffffff81b9bfde #1 [ffffc900008579c0] do_trap at ffffffff81023a9b #2 [ffffc90000857a10] do_error_trap at ffffffff81023b78 #3 [ffffc90000857a58] exc_stack_segment at ffffffff81be1f45 #4 [ffffc90000857a80] asm_exc_stack_segment at ffffffff81c009de #5 [ffffc90000857b08] nfs_lookup at ffffffffa0302322 [nfs] #6 [ffffc90000857b70] __lookup_slow at ffffffff813a4a5f #7 [ffffc90000857c60] walk_component at ffffffff813a86c4 #8 [ffffc90000857cb8] path_lookupat at ffffffff813a9553 #9 [ffffc90000857cf0] filename_lookup at ffffffff813ab86b Suggested-by: Trond Myklebust Fixes: 9558a007dbc3 ("NFS: Remove the label from the nfs4_lookup_res struct") Signed-off-by: Benjamin Coddington Signed-off-by: Anna Schumaker --- fs/nfs/nfs4namespace.c | 9 +++++++-- fs/nfs/nfs4proc.c | 15 +++++++-------- fs/nfs/nfs4state.c | 9 ++++++++- fs/nfs/nfs4xdr.c | 4 ++-- include/linux/nfs_xdr.h | 2 +- 5 files changed, 25 insertions(+), 14 deletions(-) diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c index 3680c8da510c97..f2dbf904c59895 100644 --- a/fs/nfs/nfs4namespace.c +++ b/fs/nfs/nfs4namespace.c @@ -417,6 +417,9 @@ static int nfs_do_refmount(struct fs_context *fc, struct rpc_clnt *client) fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL); if (!fs_locations) goto out_free; + fs_locations->fattr = nfs_alloc_fattr(); + if (!fs_locations->fattr) + goto out_free_2; /* Get locations */ dentry = ctx->clone_data.dentry; @@ -427,14 +430,16 @@ static int nfs_do_refmount(struct fs_context *fc, struct rpc_clnt *client) err = nfs4_proc_fs_locations(client, d_inode(parent), &dentry->d_name, fs_locations, page); dput(parent); if (err != 0) - goto out_free_2; + goto out_free_3; err = -ENOENT; if (fs_locations->nlocations <= 0 || fs_locations->fs_path.ncomponents <= 0) - goto out_free_2; + goto out_free_3; err = nfs_follow_referral(fc, fs_locations); +out_free_3: + kfree(fs_locations->fattr); out_free_2: kfree(fs_locations); out_free: diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 0dfdbb406f9694..337609befd1789 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4247,6 +4247,8 @@ static int nfs4_get_referral(struct rpc_clnt *client, struct inode *dir, if (locations == NULL) goto out; + locations->fattr = fattr; + status = nfs4_proc_fs_locations(client, dir, name, locations, page); if (status != 0) goto out; @@ -4256,17 +4258,14 @@ static int nfs4_get_referral(struct rpc_clnt *client, struct inode *dir, * referral. Cause us to drop into the exception handler, which * will kick off migration recovery. */ - if (nfs_fsid_equal(&NFS_SERVER(dir)->fsid, &locations->fattr.fsid)) { + if (nfs_fsid_equal(&NFS_SERVER(dir)->fsid, &fattr->fsid)) { dprintk("%s: server did not return a different fsid for" " a referral at %s\n", __func__, name->name); status = -NFS4ERR_MOVED; goto out; } /* Fixup attributes for the nfs_lookup() call to nfs_fhget() */ - nfs_fixup_referral_attributes(&locations->fattr); - - /* replace the lookup nfs_fattr with the locations nfs_fattr */ - memcpy(fattr, &locations->fattr, sizeof(struct nfs_fattr)); + nfs_fixup_referral_attributes(fattr); memset(fhandle, 0, sizeof(struct nfs_fh)); out: if (page) @@ -7979,7 +7978,7 @@ static int _nfs4_proc_fs_locations(struct rpc_clnt *client, struct inode *dir, else bitmask[1] &= ~FATTR4_WORD1_MOUNTED_ON_FILEID; - nfs_fattr_init(&fs_locations->fattr); + nfs_fattr_init(fs_locations->fattr); fs_locations->server = server; fs_locations->nlocations = 0; status = nfs4_call_sync(client, server, &msg, &args.seq_args, &res.seq_res, 0); @@ -8044,7 +8043,7 @@ static int _nfs40_proc_get_locations(struct nfs_server *server, unsigned long now = jiffies; int status; - nfs_fattr_init(&locations->fattr); + nfs_fattr_init(locations->fattr); locations->server = server; locations->nlocations = 0; @@ -8109,7 +8108,7 @@ static int _nfs41_proc_get_locations(struct nfs_server *server, }; int status; - nfs_fattr_init(&locations->fattr); + nfs_fattr_init(locations->fattr); locations->server = server; locations->nlocations = 0; diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 775c58def32c3e..2540b35ec18707 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -2116,6 +2116,11 @@ static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred dprintk("<-- %s: no memory\n", __func__); goto out; } + locations->fattr = nfs_alloc_fattr(); + if (locations->fattr == NULL) { + dprintk("<-- %s: no memory\n", __func__); + goto out; + } inode = d_inode(server->super->s_root); result = nfs4_proc_get_locations(server, NFS_FH(inode), locations, @@ -2130,7 +2135,7 @@ static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred if (!locations->nlocations) goto out; - if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) { + if (!(locations->fattr->valid & NFS_ATTR_FATTR_V4_LOCATIONS)) { dprintk("<-- %s: No fs_locations data, migration skipped\n", __func__); goto out; @@ -2155,6 +2160,8 @@ static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred out: if (page != NULL) __free_page(page); + if (locations != NULL) + kfree(locations->fattr); kfree(locations); if (result) { pr_err("NFS: migration recovery failed (server %s)\n", diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index 0b41e00e754f0b..acfe5f4bda480a 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -7080,7 +7080,7 @@ static int nfs4_xdr_dec_fs_locations(struct rpc_rqst *req, if (res->migration) { xdr_enter_page(xdr, PAGE_SIZE); status = decode_getfattr_generic(xdr, - &res->fs_locations->fattr, + res->fs_locations->fattr, NULL, res->fs_locations, res->fs_locations->server); if (status) @@ -7093,7 +7093,7 @@ static int nfs4_xdr_dec_fs_locations(struct rpc_rqst *req, goto out; xdr_enter_page(xdr, PAGE_SIZE); status = decode_getfattr_generic(xdr, - &res->fs_locations->fattr, + res->fs_locations->fattr, NULL, res->fs_locations, res->fs_locations->server); } diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h index 4a8ba84f848ee4..0e3aa0f5f324d4 100644 --- a/include/linux/nfs_xdr.h +++ b/include/linux/nfs_xdr.h @@ -1222,7 +1222,7 @@ struct nfs4_fs_location { #define NFS4_FS_LOCATIONS_MAXENTRIES 10 struct nfs4_fs_locations { - struct nfs_fattr fattr; + struct nfs_fattr *fattr; const struct nfs_server *server; struct nfs4_pathname fs_path; int nlocations;