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Zhiguo NiuandGreg Kroah-Hartman
5d604d40cd
[ Upstream commit39868685c2] The decompress_io_ctx may be released asynchronously after I/O completion. If this file is deleted immediately after read, and the kworker of processing post_read_wq has not been executed yet due to high workloads, It is possible that the inode(f2fs_inode_info) is evicted and freed before it is used f2fs_free_dic. The UAF case as below: Thread A Thread B - f2fs_decompress_end_io - f2fs_put_dic - queue_work add free_dic work to post_read_wq - do_unlink - iput - evict - call_rcu This file is deleted after read. Thread C kworker to process post_read_wq - rcu_do_batch - f2fs_free_inode - kmem_cache_free inode is freed by rcu - process_scheduled_works - f2fs_late_free_dic - f2fs_free_dic - f2fs_release_decomp_mem read (dic->inode)->i_compress_algorithm This patch store compress_algorithm and sbi in dic to avoid inode UAF. In addition, the previous solution is deprecated in [1] may cause system hang. [1] https://lore.kernel.org/all/c36ab955-c8db-4a8b-a9d0-f07b5f426c3f@kernel.org Cc: Daeho Jeong <daehojeong@google.com> Fixes:bff139b49d("f2fs: handle decompress only post processing in softirq") Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com> Signed-off-by: Baocong Liu <baocong.liu@unisoc.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> [ In Linux 6.6.y, the f2fs_vmalloc() function parameters are not related to the f2fs_sb_info structure, the code changes for f2fs_vmalloc() have not been backported. ] Signed-off-by: Bin Lan <lanbincn@139.com> Signed-off-by: Sasha Levin <sashal@kernel.org>