Revision 85bd839983778fcd0c1c043327b14a046e979b39 authored by Gu Zheng on 10 June 2015, 18:14:43 UTC, committed by Linus Torvalds on 10 June 2015, 23:43:43 UTC
Izumi found the following oops when hot re-adding a node:
BUG: unable to handle kernel paging request at ffffc90008963690
IP: __wake_up_bit+0x20/0x70
Oops: 0000 [#1] SMP
CPU: 68 PID: 1237 Comm: rs:main Q:Reg Not tainted 4.1.0-rc5 #80
Hardware name: FUJITSU PRIMEQUEST2800E/SB, BIOS PRIMEQUEST 2000 Series BIOS Version 1.87 04/28/2015
task: ffff880838df8000 ti: ffff880017b94000 task.ti: ffff880017b94000
RIP: 0010:[<ffffffff810dff80>] [<ffffffff810dff80>] __wake_up_bit+0x20/0x70
RSP: 0018:ffff880017b97be8 EFLAGS: 00010246
RAX: ffffc90008963690 RBX: 00000000003c0000 RCX: 000000000000a4c9
RDX: 0000000000000000 RSI: ffffea101bffd500 RDI: ffffc90008963648
RBP: ffff880017b97c08 R08: 0000000002000020 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8a0797c73800
R13: ffffea101bffd500 R14: 0000000000000001 R15: 00000000003c0000
FS: 00007fcc7ffff700(0000) GS:ffff880874800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90008963690 CR3: 0000000836761000 CR4: 00000000001407e0
Call Trace:
unlock_page+0x6d/0x70
generic_write_end+0x53/0xb0
xfs_vm_write_end+0x29/0x80 [xfs]
generic_perform_write+0x10a/0x1e0
xfs_file_buffered_aio_write+0x14d/0x3e0 [xfs]
xfs_file_write_iter+0x79/0x120 [xfs]
__vfs_write+0xd4/0x110
vfs_write+0xac/0x1c0
SyS_write+0x58/0xd0
system_call_fastpath+0x12/0x76
Code: 5d c3 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 48 83 ec 20 65 48 8b 04 25 28 00 00 00 48 89 45 f8 31 c0 48 8d 47 48 <48> 39 47 48 48 c7 45 e8 00 00 00 00 48 c7 45 f0 00 00 00 00 48
RIP [<ffffffff810dff80>] __wake_up_bit+0x20/0x70
RSP <ffff880017b97be8>
CR2: ffffc90008963690
Reproduce method (re-add a node)::
Hot-add nodeA --> remove nodeA --> hot-add nodeA (panic)
This seems an use-after-free problem, and the root cause is
zone->wait_table was not set to *NULL* after free it in
try_offline_node.
When hot re-add a node, we will reuse the pgdat of it, so does the zone
struct, and when add pages to the target zone, it will init the zone
first (including the wait_table) if the zone is not initialized. The
judgement of zone initialized is based on zone->wait_table:
static inline bool zone_is_initialized(struct zone *zone)
{
return !!zone->wait_table;
}
so if we do not set the zone->wait_table to *NULL* after free it, the
memory hotplug routine will skip the init of new zone when hot re-add
the node, and the wait_table still points to the freed memory, then we
will access the invalid address when trying to wake up the waiting
people after the i/o operation with the page is done, such as mentioned
above.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Reported-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Reviewed by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 5879ae5
lz4hc.c
/*
* Cryptographic API.
*
* Copyright (c) 2013 Chanho Min <chanho.min@lge.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program 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 General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/crypto.h>
#include <linux/vmalloc.h>
#include <linux/lz4.h>
struct lz4hc_ctx {
void *lz4hc_comp_mem;
};
static int lz4hc_init(struct crypto_tfm *tfm)
{
struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
ctx->lz4hc_comp_mem = vmalloc(LZ4HC_MEM_COMPRESS);
if (!ctx->lz4hc_comp_mem)
return -ENOMEM;
return 0;
}
static void lz4hc_exit(struct crypto_tfm *tfm)
{
struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
vfree(ctx->lz4hc_comp_mem);
}
static int lz4hc_compress_crypto(struct crypto_tfm *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int *dlen)
{
struct lz4hc_ctx *ctx = crypto_tfm_ctx(tfm);
size_t tmp_len = *dlen;
int err;
err = lz4hc_compress(src, slen, dst, &tmp_len, ctx->lz4hc_comp_mem);
if (err < 0)
return -EINVAL;
*dlen = tmp_len;
return 0;
}
static int lz4hc_decompress_crypto(struct crypto_tfm *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int *dlen)
{
int err;
size_t tmp_len = *dlen;
size_t __slen = slen;
err = lz4_decompress_unknownoutputsize(src, __slen, dst, &tmp_len);
if (err < 0)
return -EINVAL;
*dlen = tmp_len;
return err;
}
static struct crypto_alg alg_lz4hc = {
.cra_name = "lz4hc",
.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
.cra_ctxsize = sizeof(struct lz4hc_ctx),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(alg_lz4hc.cra_list),
.cra_init = lz4hc_init,
.cra_exit = lz4hc_exit,
.cra_u = { .compress = {
.coa_compress = lz4hc_compress_crypto,
.coa_decompress = lz4hc_decompress_crypto } }
};
static int __init lz4hc_mod_init(void)
{
return crypto_register_alg(&alg_lz4hc);
}
static void __exit lz4hc_mod_fini(void)
{
crypto_unregister_alg(&alg_lz4hc);
}
module_init(lz4hc_mod_init);
module_exit(lz4hc_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LZ4HC Compression Algorithm");
MODULE_ALIAS_CRYPTO("lz4hc");
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