From 7faf14a7b0366f153284db0ad3347c457ea70136 Mon Sep 17 00:00:00 2001 From: Li Lingfeng Date: Sun, 26 Jan 2025 17:47:22 +0800 Subject: [PATCH 1/6] nfsd: clear acl_access/acl_default after releasing them If getting acl_default fails, acl_access and acl_default will be released simultaneously. However, acl_access will still retain a pointer pointing to the released posix_acl, which will trigger a WARNING in nfs3svc_release_getacl like this: ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 26 PID: 3199 at lib/refcount.c:28 refcount_warn_saturate+0xb5/0x170 Modules linked in: CPU: 26 UID: 0 PID: 3199 Comm: nfsd Not tainted 6.12.0-rc6-00079-g04ae226af01f-dirty #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 RIP: 0010:refcount_warn_saturate+0xb5/0x170 Code: cc cc 0f b6 1d b3 20 a5 03 80 fb 01 0f 87 65 48 d8 00 83 e3 01 75 e4 48 c7 c7 c0 3b 9b 85 c6 05 97 20 a5 03 01 e8 fb 3e 30 ff <0f> 0b eb cd 0f b6 1d 8a3 RSP: 0018:ffffc90008637cd8 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff83904fde RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88871ed36380 RBP: ffff888158beeb40 R08: 0000000000000001 R09: fffff520010c6f56 R10: ffffc90008637ab7 R11: 0000000000000001 R12: 0000000000000001 R13: ffff888140e77400 R14: ffff888140e77408 R15: ffffffff858b42c0 FS: 0000000000000000(0000) GS:ffff88871ed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562384d32158 CR3: 000000055cc6a000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? refcount_warn_saturate+0xb5/0x170 ? __warn+0xa5/0x140 ? refcount_warn_saturate+0xb5/0x170 ? report_bug+0x1b1/0x1e0 ? handle_bug+0x53/0xa0 ? exc_invalid_op+0x17/0x40 ? asm_exc_invalid_op+0x1a/0x20 ? tick_nohz_tick_stopped+0x1e/0x40 ? refcount_warn_saturate+0xb5/0x170 ? refcount_warn_saturate+0xb5/0x170 nfs3svc_release_getacl+0xc9/0xe0 svc_process_common+0x5db/0xb60 ? __pfx_svc_process_common+0x10/0x10 ? __rcu_read_unlock+0x69/0xa0 ? __pfx_nfsd_dispatch+0x10/0x10 ? svc_xprt_received+0xa1/0x120 ? xdr_init_decode+0x11d/0x190 svc_process+0x2a7/0x330 svc_handle_xprt+0x69d/0x940 svc_recv+0x180/0x2d0 nfsd+0x168/0x200 ? __pfx_nfsd+0x10/0x10 kthread+0x1a2/0x1e0 ? kthread+0xf4/0x1e0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x60 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 Kernel panic - not syncing: kernel: panic_on_warn set ... Clear acl_access/acl_default after posix_acl_release is called to prevent UAF from being triggered. Fixes: a257cdd0e217 ("[PATCH] NFSD: Add server support for NFSv3 ACLs.") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20241107014705.2509463-1-lilingfeng@huaweicloud.com/ Signed-off-by: Li Lingfeng Reviewed-by: Rick Macklem Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- fs/nfsd/nfs2acl.c | 2 ++ fs/nfsd/nfs3acl.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/fs/nfsd/nfs2acl.c b/fs/nfsd/nfs2acl.c index 4e3be7201b1c4..5fb202acb0fd0 100644 --- a/fs/nfsd/nfs2acl.c +++ b/fs/nfsd/nfs2acl.c @@ -84,6 +84,8 @@ static __be32 nfsacld_proc_getacl(struct svc_rqst *rqstp) fail: posix_acl_release(resp->acl_access); posix_acl_release(resp->acl_default); + resp->acl_access = NULL; + resp->acl_default = NULL; goto out; } diff --git a/fs/nfsd/nfs3acl.c b/fs/nfsd/nfs3acl.c index 5e34e98db969d..7b5433bd30197 100644 --- a/fs/nfsd/nfs3acl.c +++ b/fs/nfsd/nfs3acl.c @@ -76,6 +76,8 @@ static __be32 nfsd3_proc_getacl(struct svc_rqst *rqstp) fail: posix_acl_release(resp->acl_access); posix_acl_release(resp->acl_default); + resp->acl_access = NULL; + resp->acl_default = NULL; goto out; } From b9382e29ca538b879645899ce45d652a304e2ed2 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Sat, 25 Jan 2025 20:13:18 -0500 Subject: [PATCH 2/6] nfsd: validate the nfsd_serv pointer before calling svc_wake_up nfsd_file_dispose_list_delayed can be called from the filecache laundrette, which is shut down after the nfsd threads are shut down and the nfsd_serv pointer is cleared. If nn->nfsd_serv is NULL then there are no threads to wake. Ensure that the nn->nfsd_serv pointer is non-NULL before calling svc_wake_up in nfsd_file_dispose_list_delayed. This is safe since the svc_serv is not freed until after the filecache laundrette is cancelled. Reported-by: Salvatore Bonaccorso Closes: https://bugs.debian.org/1093734 Fixes: ffb402596147 ("nfsd: Don't leave work of closing files to a work queue") Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton Reviewed-by: NeilBrown Signed-off-by: Chuck Lever --- fs/nfsd/filecache.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index a1cdba42c4fad..78f4b5573b909 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -445,11 +445,20 @@ nfsd_file_dispose_list_delayed(struct list_head *dispose) struct nfsd_file, nf_gc); struct nfsd_net *nn = net_generic(nf->nf_net, nfsd_net_id); struct nfsd_fcache_disposal *l = nn->fcache_disposal; + struct svc_serv *serv; spin_lock(&l->lock); list_move_tail(&nf->nf_gc, &l->freeme); spin_unlock(&l->lock); - svc_wake_up(nn->nfsd_serv); + + /* + * The filecache laundrette is shut down after the + * nn->nfsd_serv pointer is cleared, but before the + * svc_serv is freed. + */ + serv = nn->nfsd_serv; + if (serv) + svc_wake_up(serv); } } From 5fb25161217370eeee86b63e47060870b67ed2b4 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 28 Jan 2025 10:05:03 +1100 Subject: [PATCH 3/6] nfsd: fix uninitialised slot info when a request is retried A recent patch moved the assignment of seq->maxslots from before the test for a resent request (which ends with a goto) to after, resulting in it not being run in that case. This results in the server returning bogus "high slot id" and "target high slot id" values. The assignments to ->maxslots and ->target_maxslots need to be *after* the out: label so that the correct values are returned in replies to requests that are served from cache. Fixes: 60aa6564317d ("nfsd: allocate new session-based DRC slots on demand.") Signed-off-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- fs/nfsd/nfs4state.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index b7a0cfd05401d..153eeea2c7c99 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4459,10 +4459,11 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, } } while (slot && --cnt > 0); } + +out: seq->maxslots = max(session->se_target_maxslots, seq->maxslots); seq->target_maxslots = session->se_target_maxslots; -out: switch (clp->cl_cb_state) { case NFSD4_CB_DOWN: seq->status_flags = SEQ4_STATUS_CB_PATH_DOWN; From d9d6b74e4be989f919498798fa40df37a74b5bb0 Mon Sep 17 00:00:00 2001 From: Olga Kornievskaia Date: Tue, 28 Jan 2025 11:58:06 -0500 Subject: [PATCH 4/6] nfsd: fix __fh_verify for localio __fh_verify() added a call to svc_xprt_set_valid() to help do connection management but during LOCALIO path rqstp argument is NULL, leading to NULL pointer dereferencing and a crash. Fixes: eccbbc7c00a5 ("nfsd: don't use sv_nrthreads in connection limiting calculations.") Signed-off-by: Olga Kornievskaia Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- fs/nfsd/nfsfh.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c index bf59f83c6224e..91bf0e6d58950 100644 --- a/fs/nfsd/nfsfh.c +++ b/fs/nfsd/nfsfh.c @@ -381,8 +381,9 @@ __fh_verify(struct svc_rqst *rqstp, error = check_nfsd_access(exp, rqstp, may_bypass_gss); if (error) goto out; - - svc_xprt_set_valid(rqstp->rq_xprt); + /* During LOCALIO call to fh_verify will be called with a NULL rqstp */ + if (rqstp) + svc_xprt_set_valid(rqstp->rq_xprt); /* Finally, check access permissions. */ error = nfsd_permission(cred, exp, dentry, access); From 036ac2778f7b28885814c6fbc07e156ad1624d03 Mon Sep 17 00:00:00 2001 From: Dai Ngo Date: Thu, 30 Jan 2025 11:01:27 -0800 Subject: [PATCH 5/6] NFSD: fix hang in nfsd4_shutdown_callback If nfs4_client is in courtesy state then there is no point to send the callback. This causes nfsd4_shutdown_callback to hang since cl_cb_inflight is not 0. This hang lasts about 15 minutes until TCP notifies NFSD that the connection was dropped. This patch modifies nfsd4_run_cb_work to skip the RPC call if nfs4_client is in courtesy state. Signed-off-by: Dai Ngo Fixes: 66af25799940 ("NFSD: add courteous server support for thread with only delegation") Cc: stable@vger.kernel.org Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- fs/nfsd/nfs4callback.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index 50e468bdb8d48..cf6d29828f4e5 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -1583,8 +1583,11 @@ nfsd4_run_cb_work(struct work_struct *work) nfsd4_process_cb_update(cb); clnt = clp->cl_cb_client; - if (!clnt) { - /* Callback channel broken, or client killed; give up: */ + if (!clnt || clp->cl_state == NFSD4_COURTESY) { + /* + * Callback channel broken, client killed or + * nfs4_client in courtesy state; give up. + */ nfsd41_destroy_cb(cb); return; } From 4990d098433db18c854e75fb0f90d941eb7d479e Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Mon, 10 Feb 2025 11:43:31 -0500 Subject: [PATCH 6/6] NFSD: Fix CB_GETATTR status fix Jeff says: Now that I look, 1b3e26a5ccbf is wrong. The patch on the ml was correct, but the one that got committed is different. It should be: status = decode_cb_op_status(xdr, OP_CB_GETATTR, &cb->cb_status); if (unlikely(status || cb->cb_status)) If "status" is non-zero, decoding failed (usu. BADXDR), but we also want to bail out and not decode the rest of the call if the decoded cb_status is non-zero. That's not happening here, cb_seq_status has already been checked and is non-zero, so this ends up trying to decode the rest of the CB_GETATTR reply when it doesn't exist. Reported-by: Jeff Layton Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219737 Fixes: 1b3e26a5ccbf ("NFSD: fix decoding in nfs4_xdr_dec_cb_getattr") Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- fs/nfsd/nfs4callback.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index cf6d29828f4e5..484077200c5d7 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -679,7 +679,7 @@ static int nfs4_xdr_dec_cb_getattr(struct rpc_rqst *rqstp, return status; status = decode_cb_op_status(xdr, OP_CB_GETATTR, &cb->cb_status); - if (unlikely(status || cb->cb_seq_status)) + if (unlikely(status || cb->cb_status)) return status; if (xdr_stream_decode_uint32_array(xdr, bitmap, 3) < 0) return -NFSERR_BAD_XDR;