kernel/linux.git/fs/hostfs, branch v6.12.80

hostfs: Fix only passing host root in boot stage with new mount

2025-11-24T09:35:56+00:00

[ Upstream commit 2c2b67af5f5f77fc68261a137ad65dcfb8e52506 ] In the old mount proceedure, hostfs could only pass root directory during boot. This is because it constructed the root directory using the @root_ino event without any mount options. However, when using it with the new mount API, this step is no longer triggered. As a result, if users mounts without specifying any mount options, the @host_root_path remains uninitialized. To prevent this issue, the @host_root_path should be initialized at the time of allocation. Reported-by: Geoffrey Thorpe Closes: https://lore.kernel.org/all/643333a0-f434-42fb-82ac-d25a0b56f3b7@geoffthorpe.net/ Fixes: cd140ce9f611 ("hostfs: convert hostfs to use the new mount API") Signed-off-by: Hongbo Li Link: https://patch.msgid.link/20251011092235.29880-1-lihongbo22@huawei.com Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

um: hostfs: avoid issues on inode number reuse by host

2025-04-10T12:39:25+00:00

[ Upstream commit 0bc754d1e31f40f4a343b692096d9e092ccc0370 ] Some file systems (e.g. ext4) may reuse inode numbers once the inode is not in use anymore. Usually hostfs will keep an FD open for each inode, but this is not always the case. In the case of sockets, this cannot even be done properly. As such, the following sequence of events was possible: * application creates and deletes a socket * hostfs creates/deletes the socket on the host * inode is still in the hostfs cache * hostfs creates a new file * ext4 on the outside reuses the inode number * hostfs finds the socket inode for the newly created file * application receives -ENXIO when opening the file As mentioned, this can only happen if the deleted file is a special file that is never opened on the host (i.e. no .open fop). As such, to prevent issues, it is sufficient to check that the inode has the expected type. That said, also add a check for the inode birth time, just to be on the safe side. Fixes: 74ce793bcbde ("hostfs: Fix ephemeral inodes") Signed-off-by: Benjamin Berg Reviewed-by: Mickaël Salaün Tested-by: Mickaël Salaün Link: https://patch.msgid.link/20250214092822.1241575-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin

hostfs: fix string handling in __dentry_name()

2025-02-08T08:58:09+00:00

[ Upstream commit 60a6002432448bb3f291d80768ae98d62efc9c77 ] strcpy() should not be used with destination potentially overlapping the source; what's more, strscpy() in there is pointless - we already know the amount we want to copy; might as well use memcpy(). Fixes: c278e81b8a02 "hostfs: Remove open coded strcpy()" Signed-off-by: Al Viro Signed-off-by: Sasha Levin

hostfs: Fix the NULL vs IS_ERR() bug for __filemap_get_folio()

2024-12-05T13:03:04+00:00

[ Upstream commit bed2cc482600296fe04edbc38005ba2851449c10 ] The __filemap_get_folio() function returns error pointers. It never returns NULL. So use IS_ERR() to check it. Fixes: 1da86618bdce ("fs: Convert aops->write_begin to take a folio") Signed-off-by: ZhangPeng Acked-by: Johannes Berg Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin

fs: Convert aops->write_begin to take a folio

2024-08-07T09:33:21+00:00

Convert all callers from working on a page to working on one page of a folio (support for working on an entire folio can come later). Removes a lot of folio->page->folio conversions. Reviewed-by: Josef Bacik Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Christian Brauner

fs: Convert aops->write_end to take a folio

2024-08-07T09:32:02+00:00

Most callers have a folio, and most implementations operate on a folio, so remove the conversion from folio->page->folio to fit through this interface. Reviewed-by: Josef Bacik Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Christian Brauner

hostfs: Convert hostfs_write_end() to use a folio

2024-08-07T09:32:01+00:00

Convert the passed page to a folio and operate on that. Replaces four calls to compound_head() with one. Reviewed-by: Josef Bacik Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Christian Brauner

Merge tag 'vfs-6.11-rc1.fixes.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-07-27T22:11:59+00:00

Pull vfs fixes from Christian Brauner: "This contains two fixes for this merge window: VFS: - I noticed that it is possible for a privileged user to mount most filesystems with a non-initial user namespace in sb->s_user_ns. When fsopen() is called in a non-init namespace the caller's namespace is recorded in fs_context->user_ns. If the returned file descriptor is then passed to a process privileged in init_user_ns, that process can call fsconfig(fd_fs, FSCONFIG_CMD_CREATE*), creating a new superblock with sb->s_user_ns set to the namespace of the process which called fsopen(). This is problematic as only filesystems that raise FS_USERNS_MOUNT are known to be able to support a non-initial s_user_ns. Others may suffer security issues, on-disk corruption or outright crash the kernel. Prevent that by restricting such delegation to filesystems that allow FS_USERNS_MOUNT. Note, that this delegation requires a privileged process to actually create the superblock so either the privileged process is cooperaing or someone must have tricked a privileged process into operating on a fscontext file descriptor whose origin it doesn't know (a stupid idea). The bug dates back to about 5 years afaict. Misc: - Fix hostfs parsing when the mount request comes in via the legacy mount api. In the legacy mount api hostfs allows to specify the host directory mount without any key. Restore that behavior" * tag 'vfs-6.11-rc1.fixes.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: hostfs: fix the host directory parse when mounting. fs: don't allow non-init s_user_ns for filesystems without FS_USERNS_MOUNT

hostfs: fix the host directory parse when mounting.

2024-07-27T07:56:33+00:00

hostfs not keep the host directory when mounting. When the host directory is none (default), fc->source is used as the host root directory, and this is wrong. Here we use `parse_monolithic` to handle the old mount path for parsing the root directory. For new mount path, The `parse_param` is used for the host directory parse. Reported-and-tested-by: Maciej Żenczykowski Fixes: cd140ce9f611 ("hostfs: convert hostfs to use the new mount API") Link: https://lore.kernel.org/all/CANP3RGceNzwdb7w=vPf5=7BCid5HVQDmz1K5kC9JG42+HVAh_g@mail.gmail.com/ Cc: Christian Brauner Signed-off-by: Hongbo Li Link: https://lore.kernel.org/r/20240725065130.1821964-1-lihongbo22@huawei.com [brauner: minor fixes] Signed-off-by: Christian Brauner

Merge tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux

2024-07-25T19:33:08+00:00

Pull UML updates from Richard Weinberger: - Support for preemption - i386 Rust support - Huge cleanup by Benjamin Berg - UBSAN support - Removal of dead code * tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (41 commits) um: vector: always reset vp->opened um: vector: remove vp->lock um: register power-off handler um: line: always fill *error_out in setup_one_line() um: remove pcap driver from documentation um: Enable preemption in UML um: refactor TLB update handling um: simplify and consolidate TLB updates um: remove force_flush_all from fork_handler um: Do not flush MM in flush_thread um: Delay flushing syscalls until the thread is restarted um: remove copy_context_skas0 um: remove LDT support um: compress memory related stub syscalls while adding them um: Rework syscall handling um: Add generic stub_syscall6 function um: Create signal stack memory assignment in stub_data um: Remove stub-data.h include from common-offsets.h um: time-travel: fix signal blocking race/hang um: time-travel: remove time_exit() ...