From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4781222D7A8; Tue, 20 May 2025 13:53:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747749217; cv=none; b=L6cmzN+tm1cwiVk2NPKP7yp/BWTO+LC/8N+VXfdnxX8ApaQAHxMUCzk1lrPl51Xpp5KMtd+T91/CLCGGZt99KUPRCTo4I6WEyl/Qb9o6SkQZTGZMU0DtD+esi/2LKRHNgFHBDSuJ1fGGsqck4vVAlNyDaT6EqI/KURE5/46ojYU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747749217; c=relaxed/simple; bh=EU5RDjjZtF2mJ/8BqfbTB47IG9F8HRrqo/8ojE3fcKc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NrSq/1bysm5eQM3SKuZGSrmlDtydfe0IGHhoH+x+T0GQq/b+ygHrYzii++M4ekZ3RMiKUbx76nVJTS4kR6ac0JEe4Orn+yN56WrneLeEz8jxrjnAgLE0F6n6iUQTIvUSByqUz/eCU1iZLG2lNSRFqjklruV74iCwCmbCjvCfyWM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZatbKa0A; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ZatbKa0A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 53893C4CEE9; Tue, 20 May 2025 13:53:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1747749216; bh=EU5RDjjZtF2mJ/8BqfbTB47IG9F8HRrqo/8ojE3fcKc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZatbKa0A2sx0BD6z2hyTJFu0HVsSN/kyXt3yFXpcpBxeCjbSnkfZNqAKOnxkQg0Ew KgUVk6vUONLcv4bXkOR/KJ/fYBWnbTLfOCOTxXESB4BvQD6vSgjCKpRqCWgHmje+vt if5M5qvCd94X9042eCJ0G/nfEfQsZy3zLnt9L9gI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Li Lingfeng , Jeff Layton , Trond Myklebust , Sasha Levin Subject: [PATCH 5.15 06/59] nfs: handle failure of nfs_get_lock_context in unlock path Date: Tue, 20 May 2025 15:49:57 +0200 Message-ID: <20250520125754.090484799@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250520125753.836407405@linuxfoundation.org> References: <20250520125753.836407405@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li Lingfeng [ Upstream commit c457dc1ec770a22636b473ce5d35614adfe97636 ] When memory is insufficient, the allocation of nfs_lock_context in nfs_get_lock_context() fails and returns -ENOMEM. If we mistakenly treat an nfs4_unlockdata structure (whose l_ctx member has been set to -ENOMEM) as valid and proceed to execute rpc_run_task(), this will trigger a NULL pointer dereference in nfs4_locku_prepare. For example: BUG: kernel NULL pointer dereference, address: 000000000000000c PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 15 UID: 0 PID: 12 Comm: kworker/u64:0 Not tainted 6.15.0-rc2-dirty #60 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 Workqueue: rpciod rpc_async_schedule RIP: 0010:nfs4_locku_prepare+0x35/0xc2 Code: 89 f2 48 89 fd 48 c7 c7 68 69 ef b5 53 48 8b 8e 90 00 00 00 48 89 f3 RSP: 0018:ffffbbafc006bdb8 EFLAGS: 00010246 RAX: 000000000000004b RBX: ffff9b964fc1fa00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: fffffffffffffff4 RDI: ffff9ba53fddbf40 RBP: ffff9ba539934000 R08: 0000000000000000 R09: ffffbbafc006bc38 R10: ffffffffb6b689c8 R11: 0000000000000003 R12: ffff9ba539934030 R13: 0000000000000001 R14: 0000000004248060 R15: ffffffffb56d1c30 FS: 0000000000000000(0000) GS:ffff9ba5881f0000(0000) knlGS:00000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000000c CR3: 000000093f244000 CR4: 00000000000006f0 Call Trace: __rpc_execute+0xbc/0x480 rpc_async_schedule+0x2f/0x40 process_one_work+0x232/0x5d0 worker_thread+0x1da/0x3d0 ? __pfx_worker_thread+0x10/0x10 kthread+0x10d/0x240 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 Modules linked in: CR2: 000000000000000c ---[ end trace 0000000000000000 ]--- Free the allocated nfs4_unlockdata when nfs_get_lock_context() fails and return NULL to terminate subsequent rpc_run_task, preventing NULL pointer dereference. Fixes: f30cb757f680 ("NFS: Always wait for I/O completion before unlock") Signed-off-by: Li Lingfeng Reviewed-by: Jeff Layton Link: https://lore.kernel.org/r/20250417072508.3850532-1-lilingfeng3@huawei.com Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/nfs4proc.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 4a0691aeb7c1d..e4b3f25bb8e48 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -6835,10 +6835,18 @@ static struct nfs4_unlockdata *nfs4_alloc_unlockdata(struct file_lock *fl, struct nfs4_unlockdata *p; struct nfs4_state *state = lsp->ls_state; struct inode *inode = state->inode; + struct nfs_lock_context *l_ctx; p = kzalloc(sizeof(*p), GFP_KERNEL); if (p == NULL) return NULL; + l_ctx = nfs_get_lock_context(ctx); + if (!IS_ERR(l_ctx)) { + p->l_ctx = l_ctx; + } else { + kfree(p); + return NULL; + } p->arg.fh = NFS_FH(inode); p->arg.fl = &p->fl; p->arg.seqid = seqid; @@ -6846,7 +6854,6 @@ static struct nfs4_unlockdata *nfs4_alloc_unlockdata(struct file_lock *fl, p->lsp = lsp; /* Ensure we don't close file until we're done freeing locks! */ p->ctx = get_nfs_open_context(ctx); - p->l_ctx = nfs_get_lock_context(ctx); locks_init_lock(&p->fl); locks_copy_lock(&p->fl, fl); p->server = NFS_SERVER(inode); -- 2.39.5