UBUNTU-CVE-2026-46303
Vulnerability Summary
Timeline
Description
In the Linux kernel, the following vulnerability has been resolved: isofs: validate Rock Ridge CE continuation extent against volume size rock_continue() reads rs->cont_extent verbatim from the Rock Ridge CE record and passes it to sb_bread() without checking that the block number is within the mounted ISO 9660 volume. commit e595447e177b ("[PATCH] rock.c: handle corrupted directories") added cont_offset and cont_size rejection for the CE continuation but did not validate the extent block number itself. commit f54e18f1b831 ("isofs: Fix infinite looping over CE entries") later capped the CE chain length at RR_MAX_CE_ENTRIES = 32 but again left the block number unchecked. With a crafted ISO mounted via udisks2 (desktop optical auto-mount) or via CAP_SYS_ADMIN mount, rs->cont_extent can therefore point at an out-of-range block or at blocks belonging to an adjacent filesystem on the same block device. sb_bread() on an out-of-range block returns NULL cleanly via the block layer EIO path, so there is no memory-safety violation. For in-range reads of adjacent- filesystem data, the CE buffer is parsed as Rock Ridge records and only the text of SL sub-records reaches userspace through readlink(), which makes the info-leak channel narrow and difficult to exploit; still, rejecting the malformed CE outright matches the rejection shape already present in the same function for cont_offset and cont_size. Add an ISOFS_SB(sb)->s_nzones bounds check to rock_continue() next to the existing offset/size rejection, printing the same corrupted-directory-entry notice.
CVSS Metrics
- v4.0•MEDIUM•Score: 5.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- v3.1•HIGH•Score: 8.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Affected Systems
- ubuntu•linux
all | all | all | all | < 5.15.0-186.196 | < 6.8.0-136.136 | all | < 7.0.0-28.28
- ubuntu•linux-allwinner-5.19
all
- ubuntu•linux-aws
all | all | all | all | all
- ubuntu•linux-aws-5.0
all
- ubuntu•linux-aws-5.11
all
- ubuntu•linux-aws-5.13
all
- ubuntu•linux-aws-5.15
all
- ubuntu•linux-aws-5.19
all
- ubuntu•linux-aws-5.3
all
- ubuntu•linux-aws-5.4
all
- ubuntu•linux-aws-5.8
all
- ubuntu•linux-aws-6.14
all
- ubuntu•linux-aws-6.17
all
- ubuntu•linux-aws-6.2
all
- ubuntu•linux-aws-6.5
all
- ubuntu•linux-aws-6.8
all
- ubuntu•linux-aws-fips
all
- ubuntu•linux-aws-hwe
all
- ubuntu•linux-azure
all | all | all | all | all | all
- ubuntu•linux-azure-4.15
all
- ubuntu•linux-azure-5.11
all
- ubuntu•linux-azure-5.13
all
- ubuntu•linux-azure-5.15
all
- ubuntu•linux-azure-5.19
all
- ubuntu•linux-azure-5.3
all
- ubuntu•linux-azure-5.4
all
- ubuntu•linux-azure-5.8
all
- ubuntu•linux-azure-6.11
all
- ubuntu•linux-azure-6.14
all
- ubuntu•linux-azure-6.17
all
- ubuntu•linux-azure-6.2
all
- ubuntu•linux-azure-6.5
all
- ubuntu•linux-azure-6.8
all
- ubuntu•linux-azure-edge
all
- ubuntu•linux-azure-fde
all | all | all | all | all
- ubuntu•linux-azure-fde-5.15
all
- ubuntu•linux-azure-fde-5.19
all
- ubuntu•linux-azure-fde-6.14
all
- ubuntu•linux-azure-fde-6.17
all
- ubuntu•linux-azure-fde-6.2
all
- ubuntu•linux-azure-fde-6.8
all
- ubuntu•linux-azure-fips
all
- ubuntu•linux-azure-nvidia
all
- ubuntu•linux-azure-nvidia-6.14
all
- ubuntu•linux-bluefield
all | < 5.15.0-1096.98 | all
- ubuntu•linux-fips
all
- ubuntu•linux-gcp
all | all | all | all | all | < 5.15.0-1112.122 | < 6.8.0-1064.72 | all | < 7.0.0-1008.8
- ubuntu•linux-gcp-4.15
all
- ubuntu•linux-gcp-5.11
all
- ubuntu•linux-gcp-5.13
all
Showing first 50 affected entries in server-rendered view.
References (18)
- https://ubuntu.com/security/CVE-2026-46303
- https://www.cve.org/CVERecord?id=CVE-2026-46303
- https://git.kernel.org/linus/a36d990f591320e9dd379ab30063ebfe91d47e1f
- https://git.kernel.org/stable/c/22b36fa081f38ab397c7697f9d539211b51a0cfc
- https://git.kernel.org/stable/c/8356fb821016797f5677cbeee5ddc0d32a95b4be
- https://git.kernel.org/stable/c/a36d990f591320e9dd379ab30063ebfe91d47e1f
- https://git.kernel.org/stable/c/bf1bc673c587f5ef7e9c09b94aea7c5a7847d4d9
- https://git.kernel.org/stable/c/c9b37c8b73f6368e4750e5ccb0632c380b43c6e5
- https://git.kernel.org/stable/c/d582e12378bc1637f337622feef762f53c43fd57
- https://git.kernel.org/stable/c/e69da8eeab74b4f4505024c38a17bce060fe7df8
- https://git.kernel.org/stable/c/ef048470c90bc8c1b8318bb2ce329da9ef64b9fe
- https://ubuntu.com/security/notices/USN-8566-1
- https://ubuntu.com/security/notices/USN-8568-1
- https://ubuntu.com/security/notices/USN-8569-1
- https://ubuntu.com/security/notices/USN-8567-1
- https://ubuntu.com/security/notices/USN-8574-1
- https://ubuntu.com/security/notices/USN-8575-1
- https://ubuntu.com/security/notices/USN-8576-1