kernel/linux.git/net/sunrpc/clnt.c, branch v6.7

SUNRPC: Fix RPC client cleaned up the freed pipefs dentries

2023-11-01T19:40:44+00:00

RPC client pipefs dentries cleanup is in separated rpc_remove_pipedir() workqueue,which takes care about pipefs superblock locking. In some special scenarios, when kernel frees the pipefs sb of the current client and immediately alloctes a new pipefs sb, rpc_remove_pipedir function would misjudge the existence of pipefs sb which is not the one it used to hold. As a result, the rpc_remove_pipedir would clean the released freed pipefs dentries. To fix this issue, rpc_remove_pipedir should check whether the current pipefs sb is consistent with the original pipefs sb. This error can be catched by KASAN: ========================================================= [ 250.497700] BUG: KASAN: slab-use-after-free in dget_parent+0x195/0x200 [ 250.498315] Read of size 4 at addr ffff88800a2ab804 by task kworker/0:18/106503 [ 250.500549] Workqueue: events rpc_free_client_work [ 250.501001] Call Trace: [ 250.502880] kasan_report+0xb6/0xf0 [ 250.503209] ? dget_parent+0x195/0x200 [ 250.503561] dget_parent+0x195/0x200 [ 250.503897] ? __pfx_rpc_clntdir_depopulate+0x10/0x10 [ 250.504384] rpc_rmdir_depopulate+0x1b/0x90 [ 250.504781] rpc_remove_client_dir+0xf5/0x150 [ 250.505195] rpc_free_client_work+0xe4/0x230 [ 250.505598] process_one_work+0x8ee/0x13b0 ... [ 22.039056] Allocated by task 244: [ 22.039390] kasan_save_stack+0x22/0x50 [ 22.039758] kasan_set_track+0x25/0x30 [ 22.040109] __kasan_slab_alloc+0x59/0x70 [ 22.040487] kmem_cache_alloc_lru+0xf0/0x240 [ 22.040889] __d_alloc+0x31/0x8e0 [ 22.041207] d_alloc+0x44/0x1f0 [ 22.041514] __rpc_lookup_create_exclusive+0x11c/0x140 [ 22.041987] rpc_mkdir_populate.constprop.0+0x5f/0x110 [ 22.042459] rpc_create_client_dir+0x34/0x150 [ 22.042874] rpc_setup_pipedir_sb+0x102/0x1c0 [ 22.043284] rpc_client_register+0x136/0x4e0 [ 22.043689] rpc_new_client+0x911/0x1020 [ 22.044057] rpc_create_xprt+0xcb/0x370 [ 22.044417] rpc_create+0x36b/0x6c0 ... [ 22.049524] Freed by task 0: [ 22.049803] kasan_save_stack+0x22/0x50 [ 22.050165] kasan_set_track+0x25/0x30 [ 22.050520] kasan_save_free_info+0x2b/0x50 [ 22.050921] __kasan_slab_free+0x10e/0x1a0 [ 22.051306] kmem_cache_free+0xa5/0x390 [ 22.051667] rcu_core+0x62c/0x1930 [ 22.051995] __do_softirq+0x165/0x52a [ 22.052347] [ 22.052503] Last potentially related work creation: [ 22.052952] kasan_save_stack+0x22/0x50 [ 22.053313] __kasan_record_aux_stack+0x8e/0xa0 [ 22.053739] __call_rcu_common.constprop.0+0x6b/0x8b0 [ 22.054209] dentry_free+0xb2/0x140 [ 22.054540] __dentry_kill+0x3be/0x540 [ 22.054900] shrink_dentry_list+0x199/0x510 [ 22.055293] shrink_dcache_parent+0x190/0x240 [ 22.055703] do_one_tree+0x11/0x40 [ 22.056028] shrink_dcache_for_umount+0x61/0x140 [ 22.056461] generic_shutdown_super+0x70/0x590 [ 22.056879] kill_anon_super+0x3a/0x60 [ 22.057234] rpc_kill_sb+0x121/0x200 Fixes: 0157d021d23a ("SUNRPC: handle RPC client pipefs dentries by network namespace aware routines") Signed-off-by: felix Signed-off-by: Trond Myklebust

SUNRPC: Don't skip timeout checks in call_connect_status()

2023-10-22T23:47:56+00:00

Signed-off-by: Trond Myklebust

SUNRPC: ECONNRESET might require a rebind

2023-10-22T23:47:56+00:00

If connect() is returning ECONNRESET, it usually means that nothing is listening on that port. If so, a rebind might be required in order to obtain the new port on which the RPC service is listening. Fixes: fd01b2597941 ("SUNRPC: ECONNREFUSED should cause a rebind.") Signed-off-by: Trond Myklebust

Revert "SUNRPC dont update timeout value on connection reset"

2023-09-27T19:16:40+00:00

This reverts commit 88428cc4ae7abcc879295fbb19373dd76aad2bdd. The problem this commit is intended to fix was comprehensively fixed in commit 7de62bc09fe6 ("SUNRPC dont update timeout value on connection reset"). Since then, this commit has been preventing the correct timeout of soft mounted requests. Cc: stable@vger.kernel.org # 5.9.x: 09252177d5f9: SUNRPC: Handle major timeout in xprt_adjust_timeout() Cc: stable@vger.kernel.org # 5.9.x: 7de62bc09fe6: SUNRPC dont update timeout value on connection reset Cc: stable@vger.kernel.org # 5.9.x Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

SUNRPC: Fail quickly when server does not recognize TLS

2023-09-27T19:16:40+00:00

rpcauth_checkverf() should return a distinct error code when a server recognizes the AUTH_TLS probe but does not support TLS so that the client's header decoder can respond appropriately and quickly. No retries are necessary is in this case, since the server has already affirmatively answered "TLS is unsupported". Suggested-by: Trond Myklebust Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker

NFSv4.1: fix pnfs MDS=DS session trunking

2023-09-13T15:51:11+00:00

Currently, when GETDEVICEINFO returns multiple locations where each is a different IP but the server's identity is same as MDS, then nfs4_set_ds_client() finds the existing nfs_client structure which has the MDS's max_connect value (and if it's 1), then the 1st IP on the DS's list will get dropped due to MDS trunking rules. Other IPs would be added as they fall under the pnfs trunking rules. For the list of IPs the 1st goes thru calling nfs4_set_ds_client() which will eventually call nfs4_add_trunk() and call into rpc_clnt_test_and_add_xprt() which has the check for MDS trunking. The other IPs (after the 1st one), would call rpc_clnt_add_xprt() which doesn't go thru that check. nfs4_add_trunk() is called when MDS trunking is happening and it needs to enforce the usage of max_connect mount option of the 1st mount. However, this shouldn't be applied to pnfs flow. Instead, this patch proposed to treat MDS=DS as DS trunking and make sure that MDS's max_connect limit does not apply to the 1st IP returned in the GETDEVICEINFO list. It does so by marking the newly created client with a new flag NFS_CS_PNFS which then used to pass max_connect value to use into the rpc_clnt_test_and_add_xprt() instead of the existing rpc client's max_connect value set by the MDS connection. For example, mount was done without max_connect value set so MDS's rpc client has cl_max_connect=1. Upon calling into rpc_clnt_test_and_add_xprt() and using rpc client's value, the caller passes in max_connect value which is previously been set in the pnfs path (as a part of handling GETDEVICEINFO list of IPs) in nfs4_set_ds_client(). However, when NFS_CS_PNFS flag is not set and we know we are doing MDS trunking, comparing a new IP of the same server, we then set the max_connect value to the existing MDS's value and pass that into rpc_clnt_test_and_add_xprt(). Fixes: dc48e0abee24 ("SUNRPC enforce creation of no more than max_connect xprts") Signed-off-by: Olga Kornievskaia Signed-off-by: Anna Schumaker

Revert "SUNRPC: Fail faster on bad verifier"

2023-09-13T15:51:11+00:00

This reverts commit 0701214cd6e66585a999b132eb72ae0489beb724. The premise of this commit was incorrect. There are exactly 2 cases where rpcauth_checkverf() will return an error: 1) If there was an XDR decode problem (i.e. garbage data). 2) If gss_validate() had a problem verifying the RPCSEC_GSS MIC. In the second case, there are again 2 subcases: a) The GSS context expires, in which case gss_validate() will force a new context negotiation on retry by invalidating the cred. b) The sequence number check failed because an RPC call timed out, and the client retransmitted the request using a new sequence number, as required by RFC2203. In neither subcase is this a fatal error. Reported-by: Russell Cattelan Fixes: 0701214cd6e6 ("SUNRPC: Fail faster on bad verifier") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

SUNRPC: Mark the cred for revalidation if the server rejects it

2023-09-13T15:51:11+00:00

If the server rejects the credential as being stale, or bad, then we should mark it for revalidation before retransmitting. Fixes: 7f5667a5f8c4 ("SUNRPC: Clean up rpc_verify_header()") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

SUNRPC: Don't override connect timeouts in rpc_clnt_add_xprt()

2023-08-24T17:24:15+00:00

If the caller specifies the connect timeouts in the arguments to rpc_clnt_add_xprt(), then we shouldn't override them. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

SUNRPC: Allow specification of TCP client connect timeout at setup

2023-08-24T17:24:15+00:00

When we create a TCP transport, the connect timeout parameters are currently fixed to be 90s. This is problematic in the pNFS flexfiles case, where we may have multiple mirrors, and we would like to fail over quickly to the next mirror if a data server is down. This patch adds the ability to specify the connection parameters at RPC client creation time. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker