CVE-2021-47483

regmap: Fix possible double-free in regcache_rbtree_exit()

Description

In the Linux kernel, the following vulnerability has been resolved: regmap: Fix possible double-free in regcache_rbtree_exit() In regcache_rbtree_insert_to_block(), when 'present' realloc failed, the 'blk' which is supposed to assign to 'rbnode->block' will be freed, so 'rbnode->block' points a freed memory, in the error handling path of regcache_rbtree_init(), 'rbnode->block' will be freed again in regcache_rbtree_exit(), KASAN will report double-free as follows: BUG: KASAN: double-free or invalid-free in kfree+0xce/0x390 Call Trace: slab_free_freelist_hook+0x10d/0x240 kfree+0xce/0x390 regcache_rbtree_exit+0x15d/0x1a0 regcache_rbtree_init+0x224/0x2c0 regcache_init+0x88d/0x1310 __regmap_init+0x3151/0x4a80 __devm_regmap_init+0x7d/0x100 madera_spi_probe+0x10f/0x333 [madera_spi] spi_probe+0x183/0x210 really_probe+0x285/0xc30 To fix this, moving up the assignment of rbnode->block to immediately after the reallocation has succeeded so that the data structure stays valid even if the second reallocation fails.

Category

7.8
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.05%
Affected: Linux Linux
Affected: Linux Linux
Published at:
Updated at:

References

Link Tags
https://git.kernel.org/stable/c/e72dce9afbdbfa70d9b44f5908a50ff6c4858999 patch
https://git.kernel.org/stable/c/fc081477b47dfc3a6cb50a96087fc29674013fc2 patch
https://git.kernel.org/stable/c/758ced2c3878ff789801e6fee808e185c5cf08d6 patch
https://git.kernel.org/stable/c/3dae1a4eced3ee733d7222e69b8a55caf2d61091 patch
https://git.kernel.org/stable/c/1cead23c1c0bc766dacb900a3b0269f651ad596f patch
https://git.kernel.org/stable/c/36e911a16b377bde0ad91a8c679069d0d310b1a6 patch
https://git.kernel.org/stable/c/50cc1462a668dc62949a1127388bc3af785ce047 patch
https://git.kernel.org/stable/c/55e6d8037805b3400096d621091dfbf713f97e83 patch

Frequently Asked Questions

What is the severity of CVE-2021-47483?
CVE-2021-47483 has been scored as a high severity vulnerability.
How to fix CVE-2021-47483?
To fix CVE-2021-47483, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-47483 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-47483 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-47483?
CVE-2021-47483 affects Linux Linux, Linux Linux.
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