CVE-2025-71067

When mounting, sb->sblocksize is used to read the bootblock without being defined or validated. Set a dummy blocksize before attempting to read the boot_block.

The issue can be triggered with the following syz reproducer:

mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./file1\x00', 0x0) r4 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x121403, 0x0) ioctl$FSIOCSETFLAGS(r4, 0x40081271, &(0x7f0000000980)=0x4000) mount(&(0x7f0000000140)=@nullb, &(0x7f0000000040)='./cgroup\x00', &(0x7f0000000000)='ntfs3\x00', 0x2208004, 0x0) syz_clone(0x88200200, 0x0, 0x0, 0x0, 0x0, 0x0)

Here, the ioctl sets the bdev block size to 16384. During mount, gettreebdevflags() calls sbsetblocksize(sb, blocksize(bdev)), but since blocksize(bdev) > PAGESIZE, sbsetblocksize() leaves sb->s_blocksize at zero.

Later, ntfsinitfromboot() attempts to read the bootblock while sb->s_blocksize is still zero, which triggers the bug.

[almaz.alexandrovich@paragon-software.com: changed comment style, added return value handling]

Database specific

{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/71xxx/CVE-2025-71067.json",
    "cna_assigner": "Linux"
}

References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

28861e3bbd9e7ac4cd9c811aad71b4d116e27930

Fixed

44a38eb4f7876513db5a1bccde74de9bc4389d43

Fixed

4fff9a625da958a33191c8553a03283786f9f417

Fixed

b3c151fe8f543f1a0b8b5df16ce5d97afa5ec85a

Fixed

d1693a7d5a38acf6424235a6070bcf5b186a360d

Affected versions

v5.*

v5.14

v5.15

v5.15-rc1

v5.15-rc2

v5.15-rc3

v5.15-rc4

v5.15-rc5

v5.15-rc6

v5.15-rc7

v5.16

v5.16-rc1

v5.16-rc2

v5.16-rc3

v5.16-rc4

v5.16-rc5

v5.16-rc6

v5.16-rc7

v5.16-rc8

v5.17

v5.17-rc1

v5.17-rc2

v5.17-rc3

v5.17-rc4

v5.17-rc5

v5.17-rc6

v5.17-rc7

v5.17-rc8

v5.18

v5.18-rc1

v5.18-rc2

v5.18-rc3

v5.18-rc4

v5.18-rc5

v5.18-rc6

v5.18-rc7

v5.19

v5.19-rc1

v5.19-rc2

v5.19-rc3

v5.19-rc4

v5.19-rc5

v5.19-rc6

v5.19-rc7

v5.19-rc8

v6.*

v6.0

v6.0-rc1

v6.0-rc2

v6.0-rc3

v6.0-rc4

v6.0-rc5

v6.0-rc6

v6.0-rc7

v6.1

v6.1-rc1

v6.1-rc2

v6.1-rc3

v6.1-rc4

v6.1-rc5

v6.1-rc6

v6.1-rc7

v6.1-rc8

v6.10

v6.10-rc1

v6.10-rc2

v6.10-rc3

v6.10-rc4

v6.10-rc5

v6.10-rc6

v6.10-rc7

v6.11

v6.11-rc1

v6.11-rc2

v6.11-rc3

v6.11-rc4

v6.11-rc5

v6.11-rc6

v6.11-rc7

v6.12

v6.12-rc1

v6.12-rc2

v6.12-rc3

v6.12-rc4

v6.12-rc5

v6.12-rc6

v6.12-rc7

v6.12.1

v6.12.10

v6.12.11

v6.12.12

v6.12.13

v6.12.14

v6.12.15

v6.12.16

v6.12.17

v6.12.18

v6.12.19

v6.12.2

v6.12.20

v6.12.21

v6.12.22

v6.12.23

v6.12.24

v6.12.25

v6.12.26

v6.12.27

v6.12.28

v6.12.29

v6.12.3

v6.12.30

v6.12.31

v6.12.32

v6.12.33

v6.12.34

v6.12.35

v6.12.36

v6.12.37

v6.12.38

v6.12.39

v6.12.4

v6.12.40

v6.12.41

v6.12.42

v6.12.43

v6.12.44

v6.12.45

v6.12.46

v6.12.47

v6.12.48

v6.12.49

v6.12.5

v6.12.50

v6.12.51

v6.12.52

v6.12.53

v6.12.54

v6.12.55

v6.12.56

v6.12.57

v6.12.58

v6.12.59

v6.12.6

v6.12.60

v6.12.61

v6.12.62

v6.12.63

v6.12.7

v6.12.8

v6.12.9

v6.13

v6.13-rc1

v6.13-rc2

v6.13-rc3

v6.13-rc4

v6.13-rc5

v6.13-rc6

v6.13-rc7

v6.14

v6.14-rc1

v6.14-rc2

v6.14-rc3

v6.14-rc4

v6.14-rc5

v6.14-rc6

v6.14-rc7

v6.15

v6.15-rc1

v6.15-rc2

v6.15-rc3

v6.15-rc4

v6.15-rc5

v6.15-rc6

v6.15-rc7

v6.16

v6.16-rc1

v6.16-rc2

v6.16-rc3

v6.16-rc4

v6.16-rc5

v6.16-rc6

v6.16-rc7

v6.17

v6.17-rc1

v6.17-rc2

v6.17-rc3

v6.17-rc4

v6.17-rc5

v6.17-rc6

v6.17-rc7

v6.18

v6.18-rc1

v6.18-rc2

v6.18-rc3

v6.18-rc4

v6.18-rc5

v6.18-rc6

v6.18-rc7

v6.18.1

v6.18.2

v6.2

v6.2-rc1

v6.2-rc2

v6.2-rc3

v6.2-rc4

v6.2-rc5

v6.2-rc6

v6.2-rc7

v6.2-rc8

v6.3

v6.3-rc1

v6.3-rc2

v6.3-rc3

v6.3-rc4

v6.3-rc5

v6.3-rc6

v6.3-rc7

v6.4

v6.4-rc1

v6.4-rc2

v6.4-rc3

v6.4-rc4

v6.4-rc5

v6.4-rc6

v6.4-rc7

v6.5

v6.5-rc1

v6.5-rc2

v6.5-rc3

v6.5-rc4

v6.5-rc5

v6.5-rc6

v6.5-rc7

v6.6

v6.6-rc1

v6.6-rc2

v6.6-rc3

v6.6-rc4

v6.6-rc5

v6.6-rc6

v6.6-rc7

v6.6.1

v6.6.10

v6.6.100

v6.6.101

v6.6.102

v6.6.103

v6.6.104

v6.6.105

v6.6.106

v6.6.107

v6.6.108

v6.6.109

v6.6.11

v6.6.110

v6.6.111

v6.6.112

v6.6.113

v6.6.114

v6.6.115

v6.6.116

v6.6.117

v6.6.118

v6.6.119

v6.6.12

v6.6.13

v6.6.14

v6.6.15

v6.6.16

v6.6.17

v6.6.18

v6.6.19

v6.6.2

v6.6.20

v6.6.21

v6.6.22

v6.6.23

v6.6.24

v6.6.25

v6.6.26

v6.6.27

v6.6.28

v6.6.29

v6.6.3

v6.6.30

v6.6.31

v6.6.32

v6.6.33

v6.6.34

v6.6.35

v6.6.36

v6.6.37

v6.6.38

v6.6.39

v6.6.4

v6.6.40

v6.6.41

v6.6.42

v6.6.43

v6.6.44

v6.6.45

v6.6.46

v6.6.47

v6.6.48

v6.6.49

v6.6.5

v6.6.50

v6.6.51

v6.6.52

v6.6.53

v6.6.54

v6.6.55

v6.6.56

v6.6.57

v6.6.58

v6.6.59

v6.6.6

v6.6.60

v6.6.61

v6.6.62

v6.6.63

v6.6.64

v6.6.65

v6.6.66

v6.6.67

v6.6.68

v6.6.69

v6.6.7

v6.6.70

v6.6.71

v6.6.72

v6.6.73

v6.6.74

v6.6.75

v6.6.76

v6.6.77

v6.6.78

v6.6.79

v6.6.8

v6.6.80

v6.6.81

v6.6.82

v6.6.83

v6.6.84

v6.6.85

v6.6.86

v6.6.87

v6.6.88

v6.6.89

v6.6.9

v6.6.90

v6.6.91

v6.6.92

v6.6.93

v6.6.94

v6.6.95

v6.6.96

v6.6.97

v6.6.98

v6.6.99

v6.7

v6.7-rc1

v6.7-rc2

v6.7-rc3

v6.7-rc4

v6.7-rc5

v6.7-rc6

v6.7-rc7

v6.7-rc8

v6.8

v6.8-rc1

v6.8-rc2

v6.8-rc3

v6.8-rc4

v6.8-rc5

v6.8-rc6

v6.8-rc7

v6.9

v6.9-rc1

v6.9-rc2

v6.9-rc3

v6.9-rc4

v6.9-rc5

v6.9-rc6

v6.9-rc7

Database specific

source

"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-71067.json"

Linux / Kernel

Package

Name: Kernel

Affected ranges

Type: ECOSYSTEM
Events: Introduced

5.15.0

Fixed

6.6.120

Type: ECOSYSTEM
Events: Introduced

6.7.0

Fixed

6.12.64

Type: ECOSYSTEM
Events: Introduced

6.13.0

Fixed

6.18.3

Database specific

source

"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-71067.json"