Updated: 2023-12-06
CWE: Race Conditions
Description:
The Linux Kernel versions 2.6.38 through 4.14 have a problematic use of pmd_mkdirty() in the touch_pmd() function inside the THP implementation. touch_pmd() can be reached by get_user_pages(). In such case, the pmd will become dirty. This scenario breaks the new can_follow_write_pmd()'s logic - pmd can become dirty without going through a COW cycle. This bug is not as severe as the original "Dirty cow" because an ext4 file (or any other regular file) cannot be mapped using THP. Nevertheless, it does allow us to overwrite read-only huge pages. For example, the zero huge page and sealed shmem files can be overwritten (since their mapping can be populated using THP). Note that after the first write page-fault to the zero page, it will be replaced with a new fresh (and zeroed) thp.
CVSS3: 7
| OS | Vendor version | Errata |
|---|---|---|
| Ubuntu 16.04 | 4.4.0-103.126 | USN-3509-1 |
| Ubuntu 14.04 | 3.13.0-137.186 | USN-3510-1 |
| Ubuntu 16.04 AWS | 4.4.0-1043.52 | USN-3509-1 |
| Ubuntu 14.04 HWE | 4.4.0-103.126~14.04.1 | USN-3509-2 |
| OS | Original kernel version | State |
|---|---|---|
| Ubuntu 16.04 |
4.4.0-83.106
show all
hide all
4.4.0-98.121
4.4.0-96.119
4.4.0-91.114
4.4.0-97.120
4.4.0-89.112
4.4.0-93.116
4.4.0-101.124
4.4.0-87.110
4.4.0-92.115
|
Released |
| Ubuntu 14.04 |
3.13.0-125.174
show all
hide all
3.13.0-115.162
3.13.0-117.164
3.13.0-116.163
3.13.0-112.159
3.13.0-119.166
3.13.0-126.175
3.13.0-110.157
3.13.0-132.181
3.13.0-133.182
3.13.0-129.178
3.13.0-109.156
3.13.0-111.158
3.13.0-113.160
3.13.0-123.172
3.13.0-128.177
3.13.0-135.184
3.13.0-121.170
|
Released |
| Ubuntu 16.04 AWS |
4.4.0-1039.48
show all
hide all
4.4.0-1035.44
4.4.0-1026.35
4.4.0-1030.39
4.4.0-1038.47
4.4.0-1028.37
4.4.0-1022.31
4.4.0-1041.50
4.4.0-1031.40
4.4.0-1037.46
4.4.0-1032.41
|
Released |
| Ubuntu 14.04 HWE |
4.4.0-101.124~14.04.1
show all
hide all
4.4.0-91.114~14.04.1
4.4.0-97.120~14.04.1
4.4.0-96.119~14.04.1
4.4.0-89.112~14.04.1
4.4.0-98.121~14.04.1
4.4.0-93.116~14.04.1
4.4.0-83.106~14.04.1
4.4.0-92.115~14.04.1
4.4.0-87.110~14.04.1
|
Released |
| Debian 9 |
4.9.30-2+deb9u1
show all
hide all
4.9.51-1
4.9.30-2+deb9u5
4.9.30-2+deb9u4
4.9.30-2+deb9u3
4.9.30-2+deb9u2
4.9.30-2
|
Released |
| Debian 8 |
3.16.43-2+deb8u2
show all
hide all
3.16.43-2
3.16.7-ckt11-1+deb8u1
3.16.7-ckt25-2+deb8u1
3.16.7-ckt11-1+deb8u2
3.16.7-ckt20-1+deb8u2
3.16.7-ckt11-1+deb8u3
3.16.43-2+deb8u4
3.16.7-ckt20-1+deb8u4
3.16.7-ckt25-2+deb8u2
3.16.36-1+deb8u2
3.16.43-2+deb8u3
3.16.7-ckt25-1
3.16.7-ckt11-1+deb8u4
3.16.7-ckt25-2
3.16.7-ckt11-1+deb8u5
3.16.7-ckt20-1+deb8u3
3.16.39-1
3.16.43-2+deb8u1
3.16.7-ckt11-1+deb8u6
3.16.39-1+deb8u1
3.16.7-ckt25-2+deb8u3
3.16.43-2+deb8u5
3.16.7-ckt11-1
3.16.36-1+deb8u1
3.16.7-ckt20-1+deb8u1
3.16.39-1+deb8u2
3.16.7-ckt9-3~deb8u1
|
Released |
| Debian 8 backports |
4.9.30-2+deb9u2~bpo8+1
show all
hide all
4.9.30-2+deb9u5~bpo8+1
4.9.30-2~bpo8+1
4.9.51-1~bpo8+1
|
Released |
| Endurance 7 eig 4.14 | |
Ready For Release |