/* * fs/cifs/dns_resolve.c * * Copyright (c) 2007 Igor Mammedov * Author(s): Igor Mammedov (niallain@gmail.com) * Steve French (sfrench@us.ibm.com) * Wang Lei (wang840925@gmail.com) * David Howells (dhowells@redhat.com) * * Contains the CIFS DFS upcall routines used for hostname to * IP address translation. * * This library is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published * by the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See * the GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include #include #include "dns_resolve.h" #include "cifsglob.h" #include "cifsproto.h" #include "cifs_debug.h" /** * dns_resolve_server_name_to_ip - Resolve UNC server name to ip address. * @unc: UNC path specifying the server (with '/' as delimiter) * @ip_addr: Where to return the IP address. * * The IP address will be returned in string form, and the caller is * responsible for freeing it. * * Returns length of result on success, -ve on error. */ int dns_resolve_server_name_to_ip(const char *unc, char **ip_addr) { struct sockaddr_storage ss; const char *hostname, *sep; char *name; int len, rc; if (!ip_addr || !unc) return -EINVAL; len = strlen(unc); if (len < 3) { cifs_dbg(FYI, "%s: unc is too short: %s\n", __func__, unc); return -EINVAL; } /* Discount leading slashes for cifs */ len -= 2; hostname = unc + 2; /* Search for server name delimiter */ sep = memchr(hostname, '/', len); if (sep) len = sep - hostname; else cifs_dbg(FYI, "%s: probably server name is whole unc: %s\n", __func__, unc); /* Try to interpret hostname as an IPv4 or IPv6 address */ rc = cifs_convert_address((struct sockaddr *)&ss, hostname, len); if (rc > 0) goto name_is_IP_address; /* Perform the upcall */ rc = dns_query(NULL, hostname, len, NULL, ip_addr, NULL); if (rc < 0) cifs_dbg(FYI, "%s: unable to resolve: %*.*s\n", __func__, len, len, hostname); else cifs_dbg(FYI, "%s: resolved: %*.*s to %s\n", __func__, len, len, hostname, *ip_addr); return rc; name_is_IP_address: name = kmalloc(len + 1, GFP_KERNEL); if (!name) return -ENOMEM; memcpy(name, hostname, len); name[len] = 0; cifs_dbg(FYI, "%s: unc is IP, skipping dns upcall: %s\n", __func__, name); *ip_addr = name; return 0; } ath: root/drivers/usb/early/Makefile
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authorOndrej Kozina <okozina@redhat.com>2017-01-31 15:47:11 +0100
committerMike Snitzer <snitzer@redhat.com>2017-02-03 10:26:14 -0500
commitf5b0cba8f23915e92932f11eb063e37d70556a89 (patch)
tree19f7ccac636459333cca52027914d19084b1392b /drivers/usb/early/Makefile
parent4087a1fffe38106e10646606a27f10d40451862d (diff)
dm crypt: replace RCU read-side section with rwsem
The lockdep splat below hints at a bug in RCU usage in dm-crypt that was introduced with commit c538f6ec9f56 ("dm crypt: add ability to use keys from the kernel key retention service"). The kernel keyring function user_key_payload() is in fact a wrapper for rcu_dereference_protected() which must not be called with only rcu_read_lock() section mark. Unfortunately the kernel keyring subsystem doesn't currently provide an interface that allows the use of an RCU read-side section. So for now we must drop RCU in favour of rwsem until a proper function is made available in the kernel keyring subsystem. =============================== [ INFO: suspicious RCU usage. ] 4.10.0-rc5 #2 Not tainted ------------------------------- ./include/keys/user-type.h:53 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by cryptsetup/6464: #0: (&md->type_lock){+.+.+.}, at: [<ffffffffa02472a2>] dm_lock_md_type+0x12/0x20 [dm_mod] #1: (rcu_read_lock){......}, at: [<ffffffffa02822f8>] crypt_set_key+0x1d8/0x4b0 [dm_crypt] stack backtrace: CPU: 1 PID: 6464 Comm: cryptsetup Not tainted 4.10.0-rc5 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014 Call Trace: dump_stack+0x67/0x92 lockdep_rcu_suspicious+0xc5/0x100 crypt_set_key+0x351/0x4b0 [dm_crypt] ? crypt_set_key+0x1d8/0x4b0 [dm_crypt] crypt_ctr+0x341/0xa53 [dm_crypt] dm_table_add_target+0x147/0x330 [dm_mod] table_load+0x111/0x350 [dm_mod] ? retrieve_status+0x1c0/0x1c0 [dm_mod] ctl_ioctl+0x1f5/0x510 [dm_mod] dm_ctl_ioctl+0xe/0x20 [dm_mod] do_vfs_ioctl+0x8e/0x690 ? ____fput+0x9/0x10 ? task_work_run+0x7e/0xa0 ? trace_hardirqs_on_caller+0x122/0x1b0 SyS_ioctl+0x3c/0x70 entry_SYSCALL_64_fastpath+0x18/0xad RIP: 0033:0x7f392c9a4ec7 RSP: 002b:00007ffef6383378 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffef63830a0 RCX: 00007f392c9a4ec7 RDX: 000000000124fcc0 RSI: 00000000c138fd09 RDI: 0000000000000005 RBP: 00007ffef6383090 R08: 00000000ffffffff R09: 00000000012482b0 R10: 2a28205d34383336 R11: 0000000000000246 R12: 00007f392d803a08 R13: 00007ffef63831e0 R14: 0000000000000000 R15: 00007f392d803a0b Fixes: c538f6ec9f56 ("dm crypt: add ability to use keys from the kernel key retention service") Reported-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Ondrej Kozina <okozina@redhat.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/usb/early/Makefile')