diff options
| author | Yang Yingliang <yangyingliang@huawei.com> | 2021-10-12 10:37:35 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-02 17:38:12 +0100 |
| commit | e72dce9afbdbfa70d9b44f5908a50ff6c4858999 (patch) | |
| tree | 2330422384de314a45eb60772e53cb83560f799b /drivers | |
| parent | 1ee34b2e09c21efdf8e9f96610f6a7b8fc458064 (diff) | |
regmap: Fix possible double-free in regcache_rbtree_exit()
commit 55e6d8037805b3400096d621091dfbf713f97e83 upstream.
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.
Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 3f4ff561bc88b ("regmap: rbtree: Make cache_present bitmap per node")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20211012023735.1632786-1-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/base/regmap/regcache-rbtree.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c index 56486d92c4e7..f868dda30da0 100644 --- a/drivers/base/regmap/regcache-rbtree.c +++ b/drivers/base/regmap/regcache-rbtree.c @@ -296,14 +296,14 @@ static int regcache_rbtree_insert_to_block(struct regmap *map, if (!blk) return -ENOMEM; + rbnode->block = blk; + if (BITS_TO_LONGS(blklen) > BITS_TO_LONGS(rbnode->blklen)) { present = krealloc(rbnode->cache_present, BITS_TO_LONGS(blklen) * sizeof(*present), GFP_KERNEL); - if (!present) { - kfree(blk); + if (!present) return -ENOMEM; - } memset(present + BITS_TO_LONGS(rbnode->blklen), 0, (BITS_TO_LONGS(blklen) - BITS_TO_LONGS(rbnode->blklen)) @@ -320,7 +320,6 @@ static int regcache_rbtree_insert_to_block(struct regmap *map, } /* update the rbnode block, its size and the base register */ - rbnode->block = blk; rbnode->blklen = blklen; rbnode->base_reg = base_reg; rbnode->cache_present = present; |