diff options
Diffstat (limited to 'fs/verity/open.c')
| -rw-r--r-- | fs/verity/open.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/fs/verity/open.c b/fs/verity/open.c index d007db0c9304..bfe0280c14e4 100644 --- a/fs/verity/open.c +++ b/fs/verity/open.c @@ -221,11 +221,20 @@ out: void fsverity_set_info(struct inode *inode, struct fsverity_info *vi) { /* - * Multiple processes may race to set ->i_verity_info, so use cmpxchg. - * This pairs with the READ_ONCE() in fsverity_get_info(). + * Multiple tasks may race to set ->i_verity_info, so use + * cmpxchg_release(). This pairs with the smp_load_acquire() in + * fsverity_get_info(). I.e., here we publish ->i_verity_info with a + * RELEASE barrier so that other tasks can ACQUIRE it. */ - if (cmpxchg(&inode->i_verity_info, NULL, vi) != NULL) + if (cmpxchg_release(&inode->i_verity_info, NULL, vi) != NULL) { + /* Lost the race, so free the fsverity_info we allocated. */ fsverity_free_info(vi); + /* + * Afterwards, the caller may access ->i_verity_info directly, + * so make sure to ACQUIRE the winning fsverity_info. + */ + (void)fsverity_get_info(inode); + } } void fsverity_free_info(struct fsverity_info *vi) |