kernel.git/net/sunrpc/auth_gss, branch linux-4.14.y

SUNRPC: ensure the matching upcall is in-flight upon downcall

2023-01-18T08:26:40Z

[ Upstream commit b18cba09e374637a0a3759d856a6bca94c133952 ] Commit 9130b8dbc6ac ("SUNRPC: allow for upcalls for the same uid but different gss service") introduced `auth` argument to __gss_find_upcall(), but in gss_pipe_downcall() it was left as NULL since it (and auth->service) was not (yet) determined. When multiple upcalls with the same uid and different service are ongoing, it could happen that __gss_find_upcall(), which returns the first match found in the pipe->in_downcall list, could not find the correct gss_msg corresponding to the downcall we are looking for. Moreover, it might return a msg which is not sent to rpc.gssd yet. We could see mount.nfs process hung in D state with multiple mount.nfs are executed in parallel. The call trace below is of CentOS 7.9 kernel-3.10.0-1160.24.1.el7.x86_64 but we observed the same hang w/ elrepo kernel-ml-6.0.7-1.el7. PID: 71258 TASK: ffff91ebd4be0000 CPU: 36 COMMAND: "mount.nfs" #0 [ffff9203ca3234f8] __schedule at ffffffffa3b8899f #1 [ffff9203ca323580] schedule at ffffffffa3b88eb9 #2 [ffff9203ca323590] gss_cred_init at ffffffffc0355818 [auth_rpcgss] #3 [ffff9203ca323658] rpcauth_lookup_credcache at ffffffffc0421ebc [sunrpc] #4 [ffff9203ca3236d8] gss_lookup_cred at ffffffffc0353633 [auth_rpcgss] #5 [ffff9203ca3236e8] rpcauth_lookupcred at ffffffffc0421581 [sunrpc] #6 [ffff9203ca323740] rpcauth_refreshcred at ffffffffc04223d3 [sunrpc] #7 [ffff9203ca3237a0] call_refresh at ffffffffc04103dc [sunrpc] #8 [ffff9203ca3237b8] __rpc_execute at ffffffffc041e1c9 [sunrpc] #9 [ffff9203ca323820] rpc_execute at ffffffffc0420a48 [sunrpc] The scenario is like this. Let's say there are two upcalls for services A and B, A -> B in pipe->in_downcall, B -> A in pipe->pipe. When rpc.gssd reads pipe to get the upcall msg corresponding to service B from pipe->pipe and then writes the response, in gss_pipe_downcall the msg corresponding to service A will be picked because only uid is used to find the msg and it is before the one for B in pipe->in_downcall. And the process waiting for the msg corresponding to service A will be woken up. Actual scheduing of that process might be after rpc.gssd processes the next msg. In rpc_pipe_generic_upcall it clears msg->errno (for A). The process is scheduled to see gss_msg->ctx == NULL and gss_msg->msg.errno == 0, therefore it cannot break the loop in gss_create_upcall and is never woken up after that. This patch adds a simple check to ensure that a msg which is not sent to rpc.gssd yet is not chosen as the matching upcall upon receiving a downcall. Signed-off-by: minoura makoto Signed-off-by: Hiroshi Shimamoto Tested-by: Hiroshi Shimamoto Cc: Trond Myklebust Fixes: 9130b8dbc6ac ("SUNRPC: allow for upcalls for same uid but different gss service") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

rpc: fix gss_svc_init cleanup on failure

2021-09-22T09:45:30Z

[ Upstream commit 5a4753446253a427c0ff1e433b9c4933e5af207c ] The failure case here should be rare, but it's obviously wrong. Signed-off-by: J. Bruce Fields Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin

rpc: fix NULL dereference on kmalloc failure

2021-04-07T10:47:00Z

[ Upstream commit 0ddc942394013f08992fc379ca04cffacbbe3dae ] I think this is unlikely but possible: svc_authenticate sets rq_authop and calls svcauth_gss_accept. The kmalloc(sizeof(*svcdata), GFP_KERNEL) fails, leaving rq_auth_data NULL, and returning SVC_DENIED. This causes svc_process_common to go to err_bad_auth, and eventually call svc_authorise. That calls ->release == svcauth_gss_release, which tries to dereference rq_auth_data. Signed-off-by: J. Bruce Fields Link: https://lore.kernel.org/linux-nfs/3F1B347F-B809-478F-A1E9-0BE98E22B0F0@oracle.com/T/#t Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin

SUNRPC: Handle 0 length opaque XDR object data properly

2021-02-23T13:00:30Z

[ Upstream commit e4a7d1f7707eb44fd953a31dd59eff82009d879c ] When handling an auth_gss downcall, it's possible to get 0-length opaque object for the acceptor. In the case of a 0-length XDR object, make sure simple_get_netobj() fills in dest->data = NULL, and does not continue to kmemdup() which will set dest->data = ZERO_SIZE_PTR for the acceptor. The trace event code can handle NULL but not ZERO_SIZE_PTR for a string, and so without this patch the rpcgss_context trace event will crash the kernel as follows: [ 162.887992] BUG: kernel NULL pointer dereference, address: 0000000000000010 [ 162.898693] #PF: supervisor read access in kernel mode [ 162.900830] #PF: error_code(0x0000) - not-present page [ 162.902940] PGD 0 P4D 0 [ 162.904027] Oops: 0000 [#1] SMP PTI [ 162.905493] CPU: 4 PID: 4321 Comm: rpc.gssd Kdump: loaded Not tainted 5.10.0 #133 [ 162.908548] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 [ 162.910978] RIP: 0010:strlen+0x0/0x20 [ 162.912505] Code: 48 89 f9 74 09 48 83 c1 01 80 39 00 75 f7 31 d2 44 0f b6 04 16 44 88 04 11 48 83 c2 01 45 84 c0 75 ee c3 0f 1f 80 00 00 00 00 <80> 3f 00 74 10 48 89 f8 48 83 c0 01 80 38 00 75 f7 48 29 f8 c3 31 [ 162.920101] RSP: 0018:ffffaec900c77d90 EFLAGS: 00010202 [ 162.922263] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000fffde697 [ 162.925158] RDX: 000000000000002f RSI: 0000000000000080 RDI: 0000000000000010 [ 162.928073] RBP: 0000000000000010 R08: 0000000000000e10 R09: 0000000000000000 [ 162.930976] R10: ffff8e698a590cb8 R11: 0000000000000001 R12: 0000000000000e10 [ 162.933883] R13: 00000000fffde697 R14: 000000010034d517 R15: 0000000000070028 [ 162.936777] FS: 00007f1e1eb93700(0000) GS:ffff8e6ab7d00000(0000) knlGS:0000000000000000 [ 162.940067] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 162.942417] CR2: 0000000000000010 CR3: 0000000104eba000 CR4: 00000000000406e0 [ 162.945300] Call Trace: [ 162.946428] trace_event_raw_event_rpcgss_context+0x84/0x140 [auth_rpcgss] [ 162.949308] ? __kmalloc_track_caller+0x35/0x5a0 [ 162.951224] ? gss_pipe_downcall+0x3a3/0x6a0 [auth_rpcgss] [ 162.953484] gss_pipe_downcall+0x585/0x6a0 [auth_rpcgss] [ 162.955953] rpc_pipe_write+0x58/0x70 [sunrpc] [ 162.957849] vfs_write+0xcb/0x2c0 [ 162.959264] ksys_write+0x68/0xe0 [ 162.960706] do_syscall_64+0x33/0x40 [ 162.962238] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 162.964346] RIP: 0033:0x7f1e1f1e57df Signed-off-by: Dave Wysochanski Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

SUNRPC: Move simple_get_bytes and simple_get_netobj into private header

2021-02-23T13:00:30Z

[ Upstream commit ba6dfce47c4d002d96cd02a304132fca76981172 ] Remove duplicated helper functions to parse opaque XDR objects and place inside new file net/sunrpc/auth_gss/auth_gss_internal.h. In the new file carry the license and copyright from the source file net/sunrpc/auth_gss/auth_gss.c. Finally, update the comment inside include/linux/sunrpc/xdr.h since lockd is not the only user of struct xdr_netobj. Signed-off-by: Dave Wysochanski Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

sunrpc: clean up properly in gss_mech_unregister()

2020-06-20T08:25:20Z

commit 24c5efe41c29ee3e55bcf5a1c9f61ca8709622e8 upstream. gss_mech_register() calls svcauth_gss_register_pseudoflavor() for each flavour, but gss_mech_unregister() does not call auth_domain_put(). This is unbalanced and makes it impossible to reload the module. Change svcauth_gss_register_pseudoflavor() to return the registered auth_domain, and save it for later release. Cc: stable@vger.kernel.org (v2.6.12+) Link: https://bugzilla.kernel.org/show_bug.cgi?id=206651 Signed-off-by: NeilBrown Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman

sunrpc: svcauth_gss_register_pseudoflavor must reject duplicate registrations.

2020-06-20T08:25:20Z

commit d47a5dc2888fd1b94adf1553068b8dad76cec96c upstream. There is no valid case for supporting duplicate pseudoflavor registrations. Currently the silent acceptance of such registrations is hiding a bug. The rpcsec_gss_krb5 module registers 2 flavours but does not unregister them, so if you load, unload, reload the module, it will happily continue to use the old registration which now has pointers to the memory were the module was originally loaded. This could lead to unexpected results. So disallow duplicate registrations. Link: https://bugzilla.kernel.org/show_bug.cgi?id=206651 Cc: stable@vger.kernel.org (v2.6.12+) Signed-off-by: NeilBrown Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman

sunrpc: expiry_time should be seconds not timeval

2020-02-14T21:32:15Z

commit 3d96208c30f84d6edf9ab4fac813306ac0d20c10 upstream. When upcalling gssproxy, cache_head.expiry_time is set as a timeval, not seconds since boot. As such, RPC cache expiry logic will not clean expired objects created under auth.rpcsec.context cache. This has proven to cause kernel memory leaks on field. Using 64 bit variants of getboottime/timespec Expiration times have worked this way since 2010's c5b29f885afe "sunrpc: use seconds since boot in expiry cache". The gssproxy code introduced in 2012 added gss_proxy_save_rsc and introduced the bug. That's a while for this to lurk, but it required a bit of an extreme case to make it obvious. Signed-off-by: Roberto Bergantinos Corpas Cc: stable@vger.kernel.org Fixes: 030d794bf498 "SUNRPC: Use gssproxy upcall for server..." Tested-By: Frank Sorenson Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman

SUNRPC: Fix a compile warning for cmpxchg64()

2019-12-01T08:13:42Z

[ Upstream commit e732f4485a150492b286f3efc06f9b34dd6b9995 ] Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

sunrpc: fix 4 more call sites that were using stack memory with a scatterlist

2019-02-23T08:06:43Z

commit e7afe6c1d486b516ed586dcc10b3e7e3e85a9c2b upstream. While trying to reproduce a reported kernel panic on arm64, I discovered that AUTH_GSS basically doesn't work at all with older enctypes on arm64 systems with CONFIG_VMAP_STACK enabled. It turns out there still a few places using stack memory with scatterlists, causing krb5_encrypt() and krb5_decrypt() to produce incorrect results (or a BUG if CONFIG_DEBUG_SG is enabled). Tested with cthon on v4.0/v4.1/v4.2 with krb5/krb5i/krb5p using des3-cbc-sha1 and arcfour-hmac-md5. Signed-off-by: Scott Mayhew Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman