user/sven/linux.git/fs, branch v4.9.306

cifs: fix double free race when mount fails in cifs_get_root()

2022-03-08T18:00:57Z

[ Upstream commit 3d6cc9898efdfb062efb74dc18cfc700e082f5d5 ] When cifs_get_root() fails during cifs_smb3_do_mount() we call deactivate_locked_super() which eventually will call delayed_free() which will free the context. In this situation we should not proceed to enter the out: section in cifs_smb3_do_mount() and free the same resources a second time. [Thu Feb 10 12:59:06 2022] BUG: KASAN: use-after-free in rcu_cblist_dequeue+0x32/0x60 [Thu Feb 10 12:59:06 2022] Read of size 8 at addr ffff888364f4d110 by task swapper/1/0 [Thu Feb 10 12:59:06 2022] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G OE 5.17.0-rc3+ #4 [Thu Feb 10 12:59:06 2022] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.0 12/17/2019 [Thu Feb 10 12:59:06 2022] Call Trace: [Thu Feb 10 12:59:06 2022] [Thu Feb 10 12:59:06 2022] dump_stack_lvl+0x5d/0x78 [Thu Feb 10 12:59:06 2022] print_address_description.constprop.0+0x24/0x150 [Thu Feb 10 12:59:06 2022] ? rcu_cblist_dequeue+0x32/0x60 [Thu Feb 10 12:59:06 2022] kasan_report.cold+0x7d/0x117 [Thu Feb 10 12:59:06 2022] ? rcu_cblist_dequeue+0x32/0x60 [Thu Feb 10 12:59:06 2022] __asan_load8+0x86/0xa0 [Thu Feb 10 12:59:06 2022] rcu_cblist_dequeue+0x32/0x60 [Thu Feb 10 12:59:06 2022] rcu_core+0x547/0xca0 [Thu Feb 10 12:59:06 2022] ? call_rcu+0x3c0/0x3c0 [Thu Feb 10 12:59:06 2022] ? __this_cpu_preempt_check+0x13/0x20 [Thu Feb 10 12:59:06 2022] ? lock_is_held_type+0xea/0x140 [Thu Feb 10 12:59:06 2022] rcu_core_si+0xe/0x10 [Thu Feb 10 12:59:06 2022] __do_softirq+0x1d4/0x67b [Thu Feb 10 12:59:06 2022] __irq_exit_rcu+0x100/0x150 [Thu Feb 10 12:59:06 2022] irq_exit_rcu+0xe/0x30 [Thu Feb 10 12:59:06 2022] sysvec_hyperv_stimer0+0x9d/0xc0 ... [Thu Feb 10 12:59:07 2022] Freed by task 58179: [Thu Feb 10 12:59:07 2022] kasan_save_stack+0x26/0x50 [Thu Feb 10 12:59:07 2022] kasan_set_track+0x25/0x30 [Thu Feb 10 12:59:07 2022] kasan_set_free_info+0x24/0x40 [Thu Feb 10 12:59:07 2022] ____kasan_slab_free+0x137/0x170 [Thu Feb 10 12:59:07 2022] __kasan_slab_free+0x12/0x20 [Thu Feb 10 12:59:07 2022] slab_free_freelist_hook+0xb3/0x1d0 [Thu Feb 10 12:59:07 2022] kfree+0xcd/0x520 [Thu Feb 10 12:59:07 2022] cifs_smb3_do_mount+0x149/0xbe0 [cifs] [Thu Feb 10 12:59:07 2022] smb3_get_tree+0x1a0/0x2e0 [cifs] [Thu Feb 10 12:59:07 2022] vfs_get_tree+0x52/0x140 [Thu Feb 10 12:59:07 2022] path_mount+0x635/0x10c0 [Thu Feb 10 12:59:07 2022] __x64_sys_mount+0x1bf/0x210 [Thu Feb 10 12:59:07 2022] do_syscall_64+0x5c/0xc0 [Thu Feb 10 12:59:07 2022] entry_SYSCALL_64_after_hwframe+0x44/0xae [Thu Feb 10 12:59:07 2022] Last potentially related work creation: [Thu Feb 10 12:59:07 2022] kasan_save_stack+0x26/0x50 [Thu Feb 10 12:59:07 2022] __kasan_record_aux_stack+0xb6/0xc0 [Thu Feb 10 12:59:07 2022] kasan_record_aux_stack_noalloc+0xb/0x10 [Thu Feb 10 12:59:07 2022] call_rcu+0x76/0x3c0 [Thu Feb 10 12:59:07 2022] cifs_umount+0xce/0xe0 [cifs] [Thu Feb 10 12:59:07 2022] cifs_kill_sb+0xc8/0xe0 [cifs] [Thu Feb 10 12:59:07 2022] deactivate_locked_super+0x5d/0xd0 [Thu Feb 10 12:59:07 2022] cifs_smb3_do_mount+0xab9/0xbe0 [cifs] [Thu Feb 10 12:59:07 2022] smb3_get_tree+0x1a0/0x2e0 [cifs] [Thu Feb 10 12:59:07 2022] vfs_get_tree+0x52/0x140 [Thu Feb 10 12:59:07 2022] path_mount+0x635/0x10c0 [Thu Feb 10 12:59:07 2022] __x64_sys_mount+0x1bf/0x210 [Thu Feb 10 12:59:07 2022] do_syscall_64+0x5c/0xc0 [Thu Feb 10 12:59:07 2022] entry_SYSCALL_64_after_hwframe+0x44/0xae Reported-by: Shyam Prasad N Reviewed-by: Shyam Prasad N Signed-off-by: Ronnie Sahlberg Signed-off-by: Steve French Signed-off-by: Sasha Levin

fget: clarify and improve __fget_files() implementation

2022-03-02T10:32:07Z

commit e386dfc56f837da66d00a078e5314bc8382fab83 upstream. Commit 054aa8d439b9 ("fget: check that the fd still exists after getting a ref to it") fixed a race with getting a reference to a file just as it was being closed. It was a fairly minimal patch, and I didn't think re-checking the file pointer lookup would be a measurable overhead, since it was all right there and cached. But I was wrong, as pointed out by the kernel test robot. The 'poll2' case of the will-it-scale.per_thread_ops benchmark regressed quite noticeably. Admittedly it seems to be a very artificial test: doing "poll()" system calls on regular files in a very tight loop in multiple threads. That means that basically all the time is spent just looking up file descriptors without ever doing anything useful with them (not that doing 'poll()' on a regular file is useful to begin with). And as a result it shows the extra "re-check fd" cost as a sore thumb. Happily, the regression is fixable by just writing the code to loook up the fd to be better and clearer. There's still a cost to verify the file pointer, but now it's basically in the noise even for that benchmark that does nothing else - and the code is more understandable and has better comments too. [ Side note: this patch is also a classic case of one that looks very messy with the default greedy Myers diff - it's much more legible with either the patience of histogram diff algorithm ] Link: https://lore.kernel.org/lkml/20211210053743.GA36420@xsang-OptiPlex-9020/ Link: https://lore.kernel.org/lkml/20211213083154.GA20853@linux.intel.com/ Reported-by: kernel test robot Tested-by: Carel Si Cc: Jann Horn Cc: Miklos Szeredi Signed-off-by: Linus Torvalds Signed-off-by: Baokun Li Signed-off-by: Greg Kroah-Hartman

tracefs: Set the group ownership in apply_options() not parse_options()

2022-03-02T10:32:05Z

commit 851e99ebeec3f4a672bb5010cf1ece095acee447 upstream. Al Viro brought it to my attention that the dentries may not be filled when the parse_options() is called, causing the call to set_gid() to possibly crash. It should only be called if parse_options() succeeds totally anyway. He suggested the logical place to do the update is in apply_options(). Link: https://lore.kernel.org/all/20220225165219.737025658@goodmis.org/ Link: https://lkml.kernel.org/r/20220225153426.1c4cab6b@gandalf.local.home Cc: stable@vger.kernel.org Acked-by: Al Viro Reported-by: Al Viro Fixes: 48b27b6b5191 ("tracefs: Set all files to the same group ownership as the mount option") Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

configfs: fix a race in configfs_{,un}register_subsystem()

2022-03-02T10:32:03Z

[ Upstream commit 84ec758fb2daa236026506868c8796b0500c047d ] When configfs_register_subsystem() or configfs_unregister_subsystem() is executing link_group() or unlink_group(), it is possible that two processes add or delete list concurrently. Some unfortunate interleavings of them can cause kernel panic. One of cases is: A --> B --> C --> D A <-- B <-- C <-- D delete list_head *B | delete list_head *C --------------------------------|----------------------------------- configfs_unregister_subsystem | configfs_unregister_subsystem unlink_group | unlink_group unlink_obj | unlink_obj list_del_init | list_del_init __list_del_entry | __list_del_entry __list_del | __list_del // next == C | next->prev = prev | | next->prev = prev prev->next = next | | // prev == B | prev->next = next Fix this by adding mutex when calling link_group() or unlink_group(), but parent configfs_subsystem is NULL when config_item is root. So I create a mutex configfs_subsystem_mutex. Fixes: 7063fbf22611 ("[PATCH] configfs: User-driven configuration filesystem") Signed-off-by: ChenXiaoSong Signed-off-by: Laibin Qiu Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin

NFS: Do not report writeback errors in nfs_getattr()

2022-02-23T10:56:41Z

[ Upstream commit d19e0183a88306acda07f4a01fedeeffe2a2a06b ] The result of the writeback, whether it is an ENOSPC or an EIO, or anything else, does not inhibit the NFS client from reporting the correct file timestamps. Fixes: 79566ef018f5 ("NFS: Getattr doesn't require data sync semantics") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin

NFS: LOOKUP_DIRECTORY is also ok with symlinks

2022-02-23T10:56:40Z

commit e0caaf75d443e02e55e146fd75fe2efc8aed5540 upstream. Commit ac795161c936 (NFSv4: Handle case where the lookup of a directory fails) [1], part of Linux since 5.17-rc2, introduced a regression, where a symbolic link on an NFS mount to a directory on another NFS does not resolve(?) the first time it is accessed: Reported-by: Paul Menzel Fixes: ac795161c936 ("NFSv4: Handle case where the lookup of a directory fails") Signed-off-by: Trond Myklebust Tested-by: Donald Buczek Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman

quota: make dquot_quota_sync return errors from ->sync_fs

2022-02-23T10:56:39Z

[ Upstream commit dd5532a4994bfda0386eb2286ec00758cee08444 ] Strangely, dquot_quota_sync ignores the return code from the ->sync_fs call, which means that quotacalls like Q_SYNC never see the error. This doesn't seem right, so fix that. Signed-off-by: Darrick J. Wong Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Acked-by: Christian Brauner Signed-off-by: Sasha Levin

vfs: make freeze_super abort when sync_filesystem returns error

2022-02-23T10:56:39Z

[ Upstream commit 2719c7160dcfaae1f73a1c0c210ad3281c19022e ] If we fail to synchronize the filesystem while preparing to freeze the fs, abort the freeze. Signed-off-by: Darrick J. Wong Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Acked-by: Christian Brauner Signed-off-by: Sasha Levin

btrfs: send: in case of IO error log it

2022-02-23T10:56:39Z

commit 2e7be9db125a0bf940c5d65eb5c40d8700f738b5 upstream. Currently if we get IO error while doing send then we abort without logging information about which file caused issue. So log it to help with debugging. CC: stable@vger.kernel.org # 4.9+ Signed-off-by: Dāvis Mosāns Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

NFSv4 remove zero number of fs_locations entries error check

2022-02-16T11:43:53Z

[ Upstream commit 90e12a3191040bd3854d3e236c35921e4e92a044 ] Remove the check for the zero length fs_locations reply in the xdr decoding, and instead check for that in the migration code. Signed-off-by: Olga Kornievskaia Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin