CVE-2022-50752: In the Linux kernel, the following vulnerability has been resolved:  md/raid5: Remove unnecessary bio_put() in raid5_read_one_chunk()  When running chunk-sized reads on disks with badblocks duplicate bio free/puts are observed:     =============================================================================    BUG bio-200 (Not tainted): Object already free    -----------------------------------------------------------------------------    Allocated in mempool_alloc_slab+0x17/0x20 age=3 cpu=2 pid=7504     __slab_alloc.constprop.0+0x5a/0xb0     kmem_cache_alloc+0x31e/0x330     mempool_alloc_slab+0x17/0x20     mempool_alloc+0x100/0x2b0     bio_alloc_bioset+0x181/0x460     do_mpage_readpage+0x776/0xd00     mpage_readahead+0x166/0x320     blkdev_readahead+0x15/0x20     read_pages+0x13f/0x5f0     page_cache_ra_unbounded+0x18d/0x220     force_page_cache_ra+0x181/0x1c0     page_cache_sync_ra+0x65/0xb0     filemap_get_pages+0x1df/0xaf0     filemap_read+0x1e1/0x700     blkdev_read_iter+0x1e5/0x330     vfs_read+0x42a/0x570    Freed in mempool_free_slab+0x17/0x20 age=3 cpu=2 pid=7504     kmem_cache_free+0x46d/0x490     mempool_free_slab+0x17/0x20     mempool_free+0x66/0x190     bio_free+0x78/0x90     bio_put+0x100/0x1a0     raid5_make_request+0x2259/0x2450     md_handle_request+0x402/0x600     md_submit_bio+0xd9/0x120     __submit_bio+0x11f/0x1b0     submit_bio_noacct_nocheck+0x204/0x480     submit_bio_noacct+0x32e/0xc70     submit_bio+0x98/0x1a0     mpage_readahead+0x250/0x320     blkdev_readahead+0x15/0x20     read_pages+0x13f/0x5f0     page_cache_ra_unbounded+0x18d/0x220    Slab 0xffffea000481b600 objects=21 used=0 fp=0xffff8881206d8940 flags=0x17ffffc0010201(locked|slab|head|node=0|zone=2|lastcpupid=0x1fffff)    CPU: 0 PID: 34525 Comm: kworker/u24:2 Not tainted 6.0.0-rc2-localyes-265166-gf11c5343fa3f #143    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014    Workqueue: raid5wq raid5_do_work    Call Trace:     <TASK>     dump_stack_lvl+0x5a/0x78     dump_stack+0x10/0x16     print_trailer+0x158/0x165     object_err+0x35/0x50     free_debug_processing.cold+0xb7/0xbe     __slab_free+0x1ae/0x330     kmem_cache_free+0x46d/0x490     mempool_free_slab+0x17/0x20     mempool_free+0x66/0x190     bio_free+0x78/0x90     bio_put+0x100/0x1a0     mpage_end_io+0x36/0x150     bio_endio+0x2fd/0x360     md_end_io_acct+0x7e/0x90     bio_endio+0x2fd/0x360     handle_failed_stripe+0x960/0xb80     handle_stripe+0x1348/0x3760     handle_active_stripes.constprop.0+0x72a/0xaf0     raid5_do_work+0x177/0x330     process_one_work+0x616/0xb20     worker_thread+0x2bd/0x6f0     kthread+0x179/0x1b0     ret_from_fork+0x22/0x30     </TASK>  The double free is caused by an unnecessary bio_put() in the if(is_badblock(...)) error path in raid5_read_one_chunk().  The error path was moved ahead of bio_alloc_clone() in c82aa1b76787c ("md/raid5: move checking badblock before clone bio in raid5_read_one_chunk"). The previous code checked and freed align_bio which required a bio_put. After the move that is no longer needed as raid_bio is returned to the control of the common io path which performs its own endio resulting in a double free on bad device blocks.