From: David Howells dhowells@redhat.com

stable inclusion from stable-v5.14.9 commit e66fc460d6dcf85cf12288e133a081205aebcd97 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9R4M4 CVE: CVE-2021-47366

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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[ Upstream commit b537a3c21775075395af475dcc6ef212fcf29db8 ]

AFS-3 has two data fetch RPC variants, FS.FetchData and FS.FetchData64, and Linux's afs client switches between them when talking to a non-YFS server if the read size, the file position or the sum of the two have the upper 32 bits set of the 64-bit value.

This is a problem, however, since the file position and length fields of FS.FetchData are *signed* 32-bit values.

Fix this by capturing the capability bits obtained from the fileserver when it's sent an FS.GetCapabilities RPC, rather than just discarding them, and then picking out the VICED_CAPABILITY_64BITFILES flag. This can then be used to decide whether to use FS.FetchData or FS.FetchData64 - and also FS.StoreData or FS.StoreData64 - rather than using upper_32_bits() to switch on the parameter values.

This capabilities flag could also be used to limit the maximum size of the file, but all servers must be checked for that.

Note that the issue does not exist with FS.StoreData - that uses *unsigned* 32-bit values. It's also not a problem with Auristor servers as its YFS.FetchData64 op uses unsigned 64-bit values.

This can be tested by cloning a git repo through an OpenAFS client to an OpenAFS server and then doing "git status" on it from a Linux afs client[1]. Provided the clone has a pack file that's in the 2G-4G range, the git status will show errors like:

error: packfile .git/objects/pack/pack-5e813c51d12b6847bbc0fcd97c2bca66da50079c.pack does not match index error: packfile .git/objects/pack/pack-5e813c51d12b6847bbc0fcd97c2bca66da50079c.pack does not match index

This can be observed in the server's FileLog with something like the following appearing:

Sun Aug 29 19:31:39 2021 SRXAFS_FetchData, Fid = 2303380852.491776.3263114, Host 192.168.11.201:7001, Id 1001 Sun Aug 29 19:31:39 2021 CheckRights: len=0, for host=192.168.11.201:7001 Sun Aug 29 19:31:39 2021 FetchData_RXStyle: Pos 18446744071815340032, Len 3154 Sun Aug 29 19:31:39 2021 FetchData_RXStyle: file size 2400758866 ... Sun Aug 29 19:31:40 2021 SRXAFS_FetchData returns 5

Note the file position of 18446744071815340032. This is the requested file position sign-extended.

Fixes: b9b1f8d5930a ("AFS: write support fixes") Reported-by: Markus Suvanto markus.suvanto@gmail.com Signed-off-by: David Howells dhowells@redhat.com Reviewed-by: Marc Dionne marc.dionne@auristor.com Tested-by: Markus Suvanto markus.suvanto@gmail.com cc: linux-afs@lists.infradead.org cc: openafs-devel@openafs.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=214217#c9 [1] Link: https://lore.kernel.org/r/951332.1631308745@warthog.procyon.org.uk/ Signed-off-by: Sasha Levin sashal@kernel.org

Conflicts: fs/afs/fs_probe.c fs/afs/fsclient.c [Simple context conflict adaptation.] Signed-off-by: Zizhi Wo wozizhi@huawei.com --- fs/afs/fs_probe.c | 8 +++++++- fs/afs/fsclient.c | 30 ++++++++++++++++++++---------- fs/afs/internal.h | 1 + fs/afs/protocol_afs.h | 15 +++++++++++++++ fs/afs/protocol_yfs.h | 6 ++++++ 5 files changed, 49 insertions(+), 11 deletions(-) create mode 100644 fs/afs/protocol_afs.h

diff --git a/fs/afs/fs_probe.c b/fs/afs/fs_probe.c index e7e98ad63a91..c0031a3ab42f 100644 --- a/fs/afs/fs_probe.c +++ b/fs/afs/fs_probe.c @@ -9,6 +9,7 @@ #include <linux/slab.h> #include "afs_fs.h" #include "internal.h" +#include "protocol_afs.h" #include "protocol_yfs.h"

static unsigned int afs_fs_probe_fast_poll_interval = 30 * HZ; @@ -102,7 +103,7 @@ void afs_fileserver_probe_result(struct afs_call *call) struct afs_addr_list *alist = call->alist; struct afs_server *server = call->server; unsigned int index = call->addr_ix; - unsigned int rtt_us = 0; + unsigned int rtt_us = 0, cap0; int ret = call->error;

_enter("%pU,%u", &server->uuid, index); @@ -159,6 +160,11 @@ void afs_fileserver_probe_result(struct afs_call *call) clear_bit(AFS_SERVER_FL_IS_YFS, &server->flags); alist->addrs[index].srx_service = call->service_id; } + cap0 = ntohl(call->tmp); + if (cap0 & AFS3_VICED_CAPABILITY_64BITFILES) + set_bit(AFS_SERVER_FL_HAS_FS64, &server->flags); + else + clear_bit(AFS_SERVER_FL_HAS_FS64, &server->flags); }

if (rxrpc_kernel_get_srtt(call->net->socket, call->rxcall, &rtt_us) && diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c index 0048a32cb040..bf1fd9d187dc 100644 --- a/fs/afs/fsclient.c +++ b/fs/afs/fsclient.c @@ -483,9 +483,7 @@ void afs_fs_fetch_data(struct afs_operation *op) struct afs_read *req = op->fetch.req; __be32 *bp;

- if (upper_32_bits(req->pos) || - upper_32_bits(req->len) || - upper_32_bits(req->pos + req->len)) + if (test_bit(AFS_SERVER_FL_HAS_FS64, &op->server->flags)) return afs_fs_fetch_data64(op);

_enter(""); @@ -1149,8 +1147,7 @@ void afs_fs_store_data(struct afs_operation *op) (unsigned long long) size, (unsigned long long) pos, (unsigned long long) i_size);

- if (upper_32_bits(pos) || upper_32_bits(i_size) || upper_32_bits(size) || - upper_32_bits(pos + size)) + if (test_bit(AFS_SERVER_FL_HAS_FS64, &op->server->flags)) return afs_fs_store_data64(op, pos, size, i_size);

call = afs_alloc_flat_call(op->net, &afs_RXFSStoreData, @@ -1264,7 +1261,7 @@ static void afs_fs_setattr_size(struct afs_operation *op) key_serial(op->key), vp->fid.vid, vp->fid.vnode);

ASSERT(attr->ia_valid & ATTR_SIZE); - if (upper_32_bits(attr->ia_size)) + if (test_bit(AFS_SERVER_FL_HAS_FS64, &op->server->flags)) return afs_fs_setattr_size64(op);

call = afs_alloc_flat_call(op->net, &afs_RXFSStoreData_as_Status, @@ -1691,20 +1688,33 @@ static int afs_deliver_fs_get_capabilities(struct afs_call *call) return ret;

count = ntohl(call->tmp); - call->count = count; call->count2 = count; - afs_extract_discard(call, count * sizeof(__be32)); + if (count == 0) { + call->unmarshall = 4; + call->tmp = 0; + break; + } + + /* Extract the first word of the capabilities to call->tmp */ + afs_extract_to_tmp(call); call->unmarshall++; fallthrough;

- /* Extract capabilities words */ case 2: ret = afs_extract_data(call, false); if (ret < 0) return ret;

- /* TODO: Examine capabilities */ + afs_extract_discard(call, (count - 1) * sizeof(__be32)); + call->unmarshall++; + fallthrough; + + /* Extract remaining capabilities words */ + case 3: + ret = afs_extract_data(call, false); + if (ret < 0) + return ret;

call->unmarshall++; break; diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 637cbe549397..8ce13fe4dd78 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -510,6 +510,7 @@ struct afs_server { #define AFS_SERVER_FL_IS_YFS 16 /* Server is YFS not AFS */ #define AFS_SERVER_FL_NO_IBULK 17 /* Fileserver doesn't support FS.InlineBulkStatus */ #define AFS_SERVER_FL_NO_RM2 18 /* Fileserver doesn't support YFS.RemoveFile2 */ +#define AFS_SERVER_FL_HAS_FS64 19 /* Fileserver supports FS.{Fetch,Store}Data64 */ atomic_t ref; /* Object refcount */ atomic_t active; /* Active user count */ u32 addr_version; /* Address list version */ diff --git a/fs/afs/protocol_afs.h b/fs/afs/protocol_afs.h new file mode 100644 index 000000000000..0c39358c8b70 --- /dev/null +++ b/fs/afs/protocol_afs.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* AFS protocol bits + * + * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + + +#define AFSCAPABILITIESMAX 196 /* Maximum number of words in a capability set */ + +/* AFS3 Fileserver capabilities word 0 */ +#define AFS3_VICED_CAPABILITY_ERRORTRANS 0x0001 /* Uses UAE errors */ +#define AFS3_VICED_CAPABILITY_64BITFILES 0x0002 /* FetchData64 & StoreData64 supported */ +#define AFS3_VICED_CAPABILITY_WRITELOCKACL 0x0004 /* Can lock a file even without lock perm */ +#define AFS3_VICED_CAPABILITY_SANEACLS 0x0008 /* ACLs reviewed for sanity - don't use */ diff --git a/fs/afs/protocol_yfs.h b/fs/afs/protocol_yfs.h index b5bd03b1d3c7..e4cd89c44c46 100644 --- a/fs/afs/protocol_yfs.h +++ b/fs/afs/protocol_yfs.h @@ -168,3 +168,9 @@ enum yfs_lock_type { yfs_LockMandatoryWrite = 0x101, yfs_LockMandatoryExtend = 0x102, }; + +/* RXYFS Viced Capability Flags */ +#define YFS_VICED_CAPABILITY_ERRORTRANS 0x0001 /* Deprecated v0.195 */ +#define YFS_VICED_CAPABILITY_64BITFILES 0x0002 /* Deprecated v0.195 */ +#define YFS_VICED_CAPABILITY_WRITELOCKACL 0x0004 /* Can lock a file even without lock perm */ +#define YFS_VICED_CAPABILITY_SANEACLS 0x0008 /* Deprecated v0.195 */