From 506ada89629ec7059b96ecfb0dc7d33ece0103ca Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 17:05:56 -0700 Subject: bpf: mark a NULL kfunc argument precise check_kfunc_arg() allows bpf_register_is_null() for nullable arguments w/o marking the underlying scalar register precise. Hence a checkpoint created on such a path would prune against arbitrary scalar value. Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)") Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov --- fs/coda/cache.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 fs/coda/cache.c (limited to 'fs/coda/cache.c') diff --git a/fs/coda/cache.c b/fs/coda/cache.c new file mode 100644 index 000000000..245131296 --- /dev/null +++ b/fs/coda/cache.c @@ -0,0 +1,121 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Cache operations for Coda. + * For Linux 2.1: (C) 1997 Carnegie Mellon University + * For Linux 2.3: (C) 2000 Carnegie Mellon University + * + * Carnegie Mellon encourages users of this code to contribute improvements + * to the Coda project http://www.coda.cs.cmu.edu/ . + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include "coda_psdev.h" +#include "coda_linux.h" +#include "coda_cache.h" + +static atomic_t permission_epoch = ATOMIC_INIT(0); + +/* replace or extend an acl cache hit */ +void coda_cache_enter(struct inode *inode, int mask) +{ + struct coda_inode_info *cii = ITOC(inode); + + spin_lock(&cii->c_lock); + cii->c_cached_epoch = atomic_read(&permission_epoch); + if (!uid_eq(cii->c_uid, current_fsuid())) { + cii->c_uid = current_fsuid(); + cii->c_cached_perm = mask; + } else + cii->c_cached_perm |= mask; + spin_unlock(&cii->c_lock); +} + +/* remove cached acl from an inode */ +void coda_cache_clear_inode(struct inode *inode) +{ + struct coda_inode_info *cii = ITOC(inode); + spin_lock(&cii->c_lock); + cii->c_cached_epoch = atomic_read(&permission_epoch) - 1; + spin_unlock(&cii->c_lock); +} + +/* remove all acl caches */ +void coda_cache_clear_all(struct super_block *sb) +{ + atomic_inc(&permission_epoch); +} + + +/* check if the mask has been matched against the acl already */ +int coda_cache_check(struct inode *inode, int mask) +{ + struct coda_inode_info *cii = ITOC(inode); + int hit; + + spin_lock(&cii->c_lock); + hit = (mask & cii->c_cached_perm) == mask && + uid_eq(cii->c_uid, current_fsuid()) && + cii->c_cached_epoch == atomic_read(&permission_epoch); + spin_unlock(&cii->c_lock); + + return hit; +} + + +/* Purging dentries and children */ +/* The following routines drop dentries which are not + in use and flag dentries which are in use to be + zapped later. + + The flags are detected by: + - coda_dentry_revalidate (for lookups) if the flag is C_PURGE + - coda_dentry_delete: to remove dentry from the cache when d_count + falls to zero + - an inode method coda_revalidate (for attributes) if the + flag is C_VATTR +*/ + +/* this won't do any harm: just flag all children */ +static void coda_flag_children(struct dentry *parent, int flag) +{ + struct dentry *de; + + spin_lock(&parent->d_lock); + rcu_read_lock(); + hlist_for_each_entry(de, &parent->d_children, d_sib) { + struct inode *inode = d_inode_rcu(de); + /* don't know what to do with negative dentries */ + if (inode) + coda_flag_inode(inode, flag); + } + rcu_read_unlock(); + spin_unlock(&parent->d_lock); +} + +void coda_flag_inode_children(struct inode *inode, int flag) +{ + struct dentry *alias_de; + + if ( !inode || !S_ISDIR(inode->i_mode)) + return; + + alias_de = d_find_alias(inode); + if (!alias_de) + return; + coda_flag_children(alias_de, flag); + shrink_dcache_parent(alias_de); + dput(alias_de); +} + -- cgit v1.3.1