7.8
CWE
415
Advisory Published
Updated

CVE-2021-47483: regmap: Fix possible double-free in regcache_rbtree_exit()

First published: Wed May 22 2024(Updated: )

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.

Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Affected SoftwareAffected VersionHow to fix
Linux Linux kernel>=3.12<4.4.291
Linux Linux kernel>=4.5<4.9.289
Linux Linux kernel>=4.10<4.14.254
Linux Linux kernel>=4.15<4.19.215
Linux Linux kernel>=4.20<5.4.157
Linux Linux kernel>=5.5<5.10.77
Linux Linux kernel>=5.11<5.14.16
Linux Linux kernel=5.15-rc1
Linux Linux kernel=5.15-rc2
Linux Linux kernel=5.15-rc3
Linux Linux kernel=5.15-rc4
Linux Linux kernel=5.15-rc5
Linux Linux kernel=5.15-rc6
Linux Linux kernel=5.15-rc7

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