CVE-2021-47218

published 2024-04-10

CVE-2021-47218: In the Linux kernel, the following vulnerability has been resolved: selinux: fix NULL-pointer dereference when hashtab allocation fails When the hash table…

Priority P4 18 medium 5.5 CVSS 3.1

AV L AC L PR L UI N S U C N I N A H

In the Linux kernel, the following vulnerability has been resolved:

selinux: fix NULL-pointer dereference when hashtab allocation fails

When the hash table slot array allocation fails in hashtab_init(),
h->size is left initialized with a non-zero value, but the h->htable
pointer is NULL. This may then cause a NULL pointer dereference, since
the policydb code relies on the assumption that even after a failed
hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called
on it. Yet, these detect an empty hashtab only by looking at the size.

Fix this by making sure that hashtab_init() always leaves behind a valid
empty hashtab when the allocation fails.

Affected

12 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 5.15.5-1 (bookworm)	linux 5.15.5-1 (bookworm)
linux	linux	—	—
linux	linux	>= 03414a49ad5f3c56988c36d2070e402ffa17feaf < b17dd53cac769dd13031b0ca34f90cc65e523fab	b17dd53cac769dd13031b0ca34f90cc65e523fab
linux	linux	>= 03414a49ad5f3c56988c36d2070e402ffa17feaf < 83c8ab8503adf56bf68dafc7a382f4946c87da79	83c8ab8503adf56bf68dafc7a382f4946c87da79
linux	linux	>= 03414a49ad5f3c56988c36d2070e402ffa17feaf < dc27f3c5d10c58069672215787a96b4fae01818b	dc27f3c5d10c58069672215787a96b4fae01818b
linux	linux_kernel	—	—
linux	linux_kernel	>= 0 < 5.10.84-1	5.10.84-1
linux	linux_kernel	>= 0 < 5.15.5-1	5.15.5-1
linux	linux_kernel	>= 0 < 5.15.5-1	5.15.5-1
linux	linux_kernel	>= 0 < 5.15.5-1	5.15.5-1
linux	linux_kernel	>= 5.11 < 5.15.5	5.15.5
linux	linux_kernel	>= 5.8 < 5.10.82	5.10.82

CVSS provenance

nvd v3.1 5.5 MEDIUM CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

osv 5.5 MEDIUM

vendor_debian 5.5 MEDIUM

vendor_redhat 5.5 MEDIUM

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CWE-476