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authorJingbo Xu <jefflexu@linux.alibaba.com>2023-11-14 15:07:04 +0800
committerGao Xiang <hsiangkao@linux.alibaba.com>2023-11-17 19:55:46 +0800
commit8bd90b6ae7856dd5000b75691d905b39b9ea5d6b (patch)
tree92de1bf8ff689fbe950102b1a5d2ae47bbb12fb7
parent914fa861e3d7803c9bbafc229652c2a69edb8b60 (diff)
downloadlinux-8bd90b6ae7856dd5000b75691d905b39b9ea5d6b.tar.gz
erofs: fix NULL dereference of dif->bdev_handle in fscache mode
Avoid NULL dereference of dif->bdev_handle, as dif->bdev_handle is NULL in fscache mode. BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:erofs_map_dev+0xbd/0x1c0 Call Trace: <TASK> erofs_fscache_data_read_slice+0xa7/0x340 erofs_fscache_data_read+0x11/0x30 erofs_fscache_readahead+0xd9/0x100 read_pages+0x47/0x1f0 page_cache_ra_order+0x1e5/0x270 filemap_get_pages+0xf2/0x5f0 filemap_read+0xb8/0x2e0 vfs_read+0x18d/0x2b0 ksys_read+0x53/0xd0 do_syscall_64+0x42/0xf0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 Reported-by: Yiqun Leng <yqleng@linux.alibaba.com> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=7245 Fixes: 49845720080d ("erofs: Convert to use bdev_open_by_path()") Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Reviewed-by: Yue Hu <huyue2@coolpad.com> Reviewed-by: Chao Yu <chao@kernel.org> Link: https://lore.kernel.org/r/20231114070704.23398-1-jefflexu@linux.alibaba.com Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
-rw-r--r--fs/erofs/data.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 029c761670bfcd..c98aeda8abb215 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -220,7 +220,7 @@ int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map)
up_read(&devs->rwsem);
return 0;
}
- map->m_bdev = dif->bdev_handle->bdev;
+ map->m_bdev = dif->bdev_handle ? dif->bdev_handle->bdev : NULL;
map->m_daxdev = dif->dax_dev;
map->m_dax_part_off = dif->dax_part_off;
map->m_fscache = dif->fscache;
@@ -238,7 +238,8 @@ int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map)
if (map->m_pa >= startoff &&
map->m_pa < startoff + length) {
map->m_pa -= startoff;
- map->m_bdev = dif->bdev_handle->bdev;
+ map->m_bdev = dif->bdev_handle ?
+ dif->bdev_handle->bdev : NULL;
map->m_daxdev = dif->dax_dev;
map->m_dax_part_off = dif->dax_part_off;
map->m_fscache = dif->fscache;