On Sun, 2024-02-04 at 02:14 +0000, Al Viro wrote: > We still have some races in filesystem methods when exposed > to RCU pathwalk. The series below is a result of code audit (the > second round of it) and it should deal with most of that stuff. > Exceptions: ntfs3 ->d_hash()/->d_compare() and ceph_d_revalidate(). > Up to maintainers (a note for NTFS folks - when documentation says > that a method may not block, it *does* imply that blocking allocations > are to be avoided. Really). > > Branch is 6.8-rc1-based; it lives in > git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git fixes.pathwalk-rcu > > Individual patches are in followups; ditto for code audit notes. Beginning > of the latter should probably be converted into docs; if anyone is willing > to help with such conversion, please say so - I'll be glad to answer any > questions, etc. > > If somebody wants to grab bits and pieces of that series into individual > filesystem git trees, please say so. Same for any problems spotted in > the patches, obviously. If nothing shows up, that goes into #fixes and > into mainline. > > Shortlog: > fs/super.c: don't drop ->s_user_ns until we free struct super_block itself > rcu pathwalk: prevent bogus hard errors from may_lookup() > affs: free affs_sb_info with kfree_rcu() > exfat: move freeing sbi, upcase table and dropping nls into rcu-delayed helper > hfsplus: switch to rcu-delayed unloading of nls and freeing ->s_fs_info > afs: fix __afs_break_callback() / afs_drop_open_mmap() race > nfs: make nfs_set_verifier() safe for use in RCU pathwalk > nfs: fix UAF on pathwalk running into umount > procfs: move dropping pde and pid from ->evict_inode() to ->free_inode() > procfs: make freeing proc_fs_info rcu-delayed > fuse: fix UAF in rcu pathwalks > cifs_get_link(): bail out in unsafe case > ext4_get_link(): fix breakage in RCU mode > > Diffstat: > fs/affs/affs.h | 1 + > fs/affs/super.c | 2 +- > fs/afs/file.c | 8 ++++++-- > fs/exfat/exfat_fs.h | 1 + > fs/exfat/nls.c | 14 ++++---------- > fs/exfat/super.c | 20 +++++++++++--------- > fs/ext4/symlink.c | 8 +++++--- > fs/fuse/cuse.c | 3 +-- > fs/fuse/fuse_i.h | 1 + > fs/fuse/inode.c | 15 +++++++++++---- > fs/hfsplus/hfsplus_fs.h | 1 + > fs/hfsplus/super.c | 12 +++++++++--- > fs/namei.c | 6 +++++- > fs/nfs/client.c | 13 ++++++++++--- > fs/nfs/dir.c | 4 ++-- > fs/proc/base.c | 2 -- > fs/proc/inode.c | 19 ++++++++----------- > fs/proc/root.c | 2 +- > fs/smb/client/cifsfs.c | 3 +++ > fs/super.c | 13 ++++--------- > include/linux/nfs_fs_sb.h | 2 ++ > include/linux/proc_fs.h | 1 + > 22 files changed, 88 insertions(+), 63 deletions(-) > Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
