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'…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.23%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.23% probability · 14th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-415
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/1cead23c1c0bc766dacb900a3b0269f651ad596fPatch
- https://git.kernel.org/stable/c/36e911a16b377bde0ad91a8c679069d0d310b1a6Patch
- https://git.kernel.org/stable/c/3dae1a4eced3ee733d7222e69b8a55caf2d61091Patch
- https://git.kernel.org/stable/c/50cc1462a668dc62949a1127388bc3af785ce047Patch
- https://git.kernel.org/stable/c/55e6d8037805b3400096d621091dfbf713f97e83Patch
- https://git.kernel.org/stable/c/758ced2c3878ff789801e6fee808e185c5cf08d6Patch
- https://git.kernel.org/stable/c/e72dce9afbdbfa70d9b44f5908a50ff6c4858999Patch
- https://git.kernel.org/stable/c/fc081477b47dfc3a6cb50a96087fc29674013fc2Patch
- https://git.kernel.org/stable/c/1cead23c1c0bc766dacb900a3b0269f651ad596fPatch
- https://git.kernel.org/stable/c/36e911a16b377bde0ad91a8c679069d0d310b1a6Patch
- https://git.kernel.org/stable/c/3dae1a4eced3ee733d7222e69b8a55caf2d61091Patch
- https://git.kernel.org/stable/c/50cc1462a668dc62949a1127388bc3af785ce047Patch
- https://git.kernel.org/stable/c/55e6d8037805b3400096d621091dfbf713f97e83Patch
- https://git.kernel.org/stable/c/758ced2c3878ff789801e6fee808e185c5cf08d6Patch
- https://git.kernel.org/stable/c/e72dce9afbdbfa70d9b44f5908a50ff6c4858999Patch
- https://git.kernel.org/stable/c/fc081477b47dfc3a6cb50a96087fc29674013fc2Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.