Re: KASAN: use-after-free Read in __list_add_valid (5)

From: Eric Biggers
Date: Sun May 13 2018 - 19:00:44 EST

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On Sun, Mar 25, 2018 at 05:01:03PM -0700, syzbot wrote:
> Hello,
>
> syzbot hit the following crash on upstream commit
> bcfc1f4554662d8f2429ac8bd96064a59c149754 (Sat Mar 24 16:50:12 2018 +0000)
> Merge tag 'pinctrl-v4.16-3' of
> git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
> syzbot dashboard link:
> https://syzkaller.appspot.com/bug?extid=db1c219466daac1083df
>
> So far this crash happened 4 times on upstream.
> C reproducer: https://syzkaller.appspot.com/x/repro.c?id=5164223906709504
> syzkaller reproducer:
> https://syzkaller.appspot.com/x/repro.syz?id=5357898477600768
> Raw console output:
> https://syzkaller.appspot.com/x/log.txt?id=5549124782915584
> Kernel config:
> https://syzkaller.appspot.com/x/.config?id=-5034017172441945317
> compiler: gcc (GCC) 7.1.1 20170620
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+db1c219466daac1083df@xxxxxxxxxxxxxxxxxxxxxxxxx
> It will help syzbot understand when the bug is fixed. See footer for
> details.
> If you forward the report, please keep this part and the footer.
>
> IPVS: ftp: loaded support on port[0] = 21
> IPVS: ftp: loaded support on port[0] = 21
> IPVS: ftp: loaded support on port[0] = 21
> ==================================================================
> BUG: KASAN: use-after-free in __list_add_valid+0xc6/0xd0 lib/list_debug.c:26
> IPVS: ftp: loaded support on port[0] = 21
> Read of size 8 at addr ffff8801ca8adcd8 by task syzkaller401155/4288
>
> CPU: 0 PID: 4288 Comm: syzkaller401155 Not tainted 4.16.0-rc6+ #365
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Call Trace:
> __dump_stack lib/dump_stack.c:17 [inline]
> dump_stack+0x194/0x24d lib/dump_stack.c:53
> print_address_description+0x73/0x250 mm/kasan/report.c:256
> IPVS: ftp: loaded support on port[0] = 21
> kasan_report_error mm/kasan/report.c:354 [inline]
> kasan_report+0x23c/0x360 mm/kasan/report.c:412
> __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
> __list_add_valid+0xc6/0xd0 lib/list_debug.c:26
> __list_add include/linux/list.h:60 [inline]
> list_add_tail include/linux/list.h:93 [inline]
> cma_listen_on_all drivers/infiniband/core/cma.c:2309 [inline]
> rdma_listen+0x581/0x8e0 drivers/infiniband/core/cma.c:3333
> ucma_listen+0x172/0x1f0 drivers/infiniband/core/ucma.c:1074
> ucma_write+0x2d6/0x3d0 drivers/infiniband/core/ucma.c:1649
> IPVS: ftp: loaded support on port[0] = 21
> __vfs_write+0xef/0x970 fs/read_write.c:480
> IPVS: ftp: loaded support on port[0] = 21
> vfs_write+0x189/0x510 fs/read_write.c:544
> SYSC_write fs/read_write.c:589 [inline]
> SyS_write+0xef/0x220 fs/read_write.c:581
> do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
> IPVS: ftp: loaded support on port[0] = 21
> entry_SYSCALL_64_after_hwframe+0x42/0xb7
> RIP: 0033:0x44a9e9
> RSP: 002b:00007f94303f3da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
> RAX: ffffffffffffffda RBX: 00000000006e29fc RCX: 000000000044a9e9
> RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000004
> RBP: 00000000006e29f8 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 2f646e6162696e69
> R13: 666e692f7665642f R14: 7073642f7665642f R15: 0000000000000009
>
> Allocated by task 4284:
> save_stack+0x43/0xd0 mm/kasan/kasan.c:447
> set_track mm/kasan/kasan.c:459 [inline]
> kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:552
> kmem_cache_alloc_trace+0x136/0x740 mm/slab.c:3607
> kmalloc include/linux/slab.h:512 [inline]
> kzalloc include/linux/slab.h:701 [inline]
> rdma_create_id+0xd0/0x630 drivers/infiniband/core/cma.c:787
> ucma_create_id+0x35f/0x920 drivers/infiniband/core/ucma.c:480
> ucma_write+0x2d6/0x3d0 drivers/infiniband/core/ucma.c:1649
> __vfs_write+0xef/0x970 fs/read_write.c:480
> vfs_write+0x189/0x510 fs/read_write.c:544
> SYSC_write fs/read_write.c:589 [inline]
> SyS_write+0xef/0x220 fs/read_write.c:581
> do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
> entry_SYSCALL_64_after_hwframe+0x42/0xb7
>
> Freed by task 4284:
> save_stack+0x43/0xd0 mm/kasan/kasan.c:447
> set_track mm/kasan/kasan.c:459 [inline]
> __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520
> kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527
> __cache_free mm/slab.c:3485 [inline]
> kfree+0xd9/0x260 mm/slab.c:3800
> rdma_destroy_id+0x821/0xda0 drivers/infiniband/core/cma.c:1691
> ucma_close+0x100/0x2f0 drivers/infiniband/core/ucma.c:1728
> __fput+0x327/0x7e0 fs/file_table.c:209
> ____fput+0x15/0x20 fs/file_table.c:243
> task_work_run+0x199/0x270 kernel/task_work.c:113
> exit_task_work include/linux/task_work.h:22 [inline]
> do_exit+0x9bb/0x1ad0 kernel/exit.c:865
> do_group_exit+0x149/0x400 kernel/exit.c:968
> get_signal+0x73a/0x16d0 kernel/signal.c:2469
> do_signal+0x90/0x1e90 arch/x86/kernel/signal.c:809
> exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:162
> prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
> syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
> do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292
> entry_SYSCALL_64_after_hwframe+0x42/0xb7
>
> The buggy address belongs to the object at ffff8801ca8adb00
> which belongs to the cache kmalloc-1024 of size 1024
> The buggy address is located 472 bytes inside of
> 1024-byte region [ffff8801ca8adb00, ffff8801ca8adf00)
> The buggy address belongs to the page:
> page:ffffea00072a2b00 count:1 mapcount:0 mapping:ffff8801ca8ac000 index:0x0
> compound_mapcount: 0
> flags: 0x2fffc0000008100(slab|head)
> raw: 02fffc0000008100 ffff8801ca8ac000 0000000000000000 0000000100000007
> raw: ffffea00072969a0 ffffea00072c5d20 ffff8801dac00ac0 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
> ffff8801ca8adb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8801ca8adc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ffff8801ca8adc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff8801ca8add00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8801ca8add80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
> This bug is generated by a dumb bot. It may contain errors.
> See https://goo.gl/tpsmEJ for details.
> Direct all questions to syzkaller@xxxxxxxxxxxxxxxxx
>
> syzbot will keep track of this bug report.
> If you forgot to add the Reported-by tag, once the fix for this bug is
> merged
> into any tree, please reply to this email with:
> #syz fix: exact-commit-title
> If you want to test a patch for this bug, please reply with:
> #syz test: git://repo/address.git branch
> and provide the patch inline or as an attachment.
> To mark this as a duplicate of another syzbot report, please reply with:
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> If it's a one-off invalid bug report, please reply with:
> #syz invalid
> Note: if the crash happens again, it will cause creation of a new bug
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Still reproducible on Linus' tree (commit 66e1c94db3cd4e) and on linux-next
(next-20180511). Here's a simplified reproducer:

#include <fcntl.h>
#include <netinet/in.h>
#include <pthread.h>
#include <rdma/rdma_user_cm.h>
#include <unistd.h>

static int cmfd;
static volatile uint64_t id;

static void *thr1(void *_ignored)
{
for (;;) {
struct {
struct rdma_ucm_cmd_hdr hdr;
struct rdma_ucm_create_id create;
} msg = {
.hdr = {
.cmd = RDMA_USER_CM_CMD_CREATE_ID,
.out = 8
},
.create = {
.response = (unsigned long)&id,
.ps = 2, /* RDMA_PS_IPOIB */
},
};
write(cmfd, &msg, sizeof(msg));
}
}

static void *thr2(void *_ignored)
{
for (;;) {
struct {
struct rdma_ucm_cmd_hdr hdr;
struct rdma_ucm_bind_ip bind;
} msg = {
.hdr = { .cmd = RDMA_USER_CM_CMD_BIND_IP },
.bind = {
.addr = {
.sin6_family = AF_INET6,
.sin6_addr = { .s6_addr = { 0xff } },
},
.id = id,
},
};
write(cmfd, &msg, sizeof(msg));
}
}

static void *thr3(void *_ignored)
{
for (;;) {
struct {
struct rdma_ucm_cmd_hdr hdr;
struct rdma_ucm_listen listen;
} msg = {
.hdr = { .cmd = RDMA_USER_CM_CMD_LISTEN },
.listen = { .id = id },
};
write(cmfd, &msg, sizeof(msg));
}
}

int main()
{
pthread_t t[3];

cmfd = open("/dev/infiniband/rdma_cm", O_WRONLY);

pthread_create(&t[0], NULL, thr1, NULL);
pthread_create(&t[1], NULL, thr2, NULL);
pthread_create(&t[2], NULL, thr3, NULL);
usleep(100000);
}

Next message: Andy Shevchenko: "Re: [PATCH v3 1/2] PCI: kirin: Add MSI support"
Previous message: Andy Shevchenko: "Re: [PATCH] drivers: bluetooth: hci_serdev: Removed unnecessary curly braces"
Next in thread: Roland Dreier: "Re: KASAN: use-after-free Read in __list_add_valid (5)"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]