CVE-2021-47483

HIGH
Published May 22, 2024 Modified Jan 6, 2025 CWE-415

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.

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CVSS v3.1 Score

7.8
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-415 CWE-415

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel

References

Advisories & Patches

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

Frequently Asked Questions

What is CVE-2021-47483? +
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. It has a CVSS v3.1 base score of 7.8 (HIGH).
How severe is CVE-2021-47483? +
CVE-2021-47483 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
What products are affected by CVE-2021-47483? +
CVE-2021-47483 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2021-47483? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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