5.10-stable review patch. If anyone has any objections, please let me know.
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From: Amir Goldstein amir73il@gmail.com
[ Upstream commit 8afd7215aa97f8868d033f6e1d01a276ab2d29c0 ]
Create helper fanotify_may_update_existing_mark() for checking for conflicts between existing mark flags and fanotify_mark() flags.
Use variable mark_cmd to make the checks for mark command bits cleaner.
Link: https://lore.kernel.org/r/20220629144210.2983229-3-amir73il@gmail.com Signed-off-by: Amir Goldstein amir73il@gmail.com Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/notify/fanotify/fanotify_user.c | 30 +++++++++++++++++++++--------- include/linux/fanotify.h | 9 +++++---- 2 files changed, 26 insertions(+), 13 deletions(-)
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 0d61cb0e49075..715e41b344129 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -1175,6 +1175,19 @@ static int fanotify_group_init_error_pool(struct fsnotify_group *group) sizeof(struct fanotify_error_event)); }
+static int fanotify_may_update_existing_mark(struct fsnotify_mark *fsn_mark, + unsigned int fan_flags) +{ + /* + * Non evictable mark cannot be downgraded to evictable mark. + */ + if (fan_flags & FAN_MARK_EVICTABLE && + !(fsn_mark->flags & FSNOTIFY_MARK_FLAG_NO_IREF)) + return -EEXIST; + + return 0; +} + static int fanotify_add_mark(struct fsnotify_group *group, fsnotify_connp_t *connp, unsigned int obj_type, __u32 mask, unsigned int fan_flags, @@ -1196,13 +1209,11 @@ static int fanotify_add_mark(struct fsnotify_group *group, }
/* - * Non evictable mark cannot be downgraded to evictable mark. + * Check if requested mark flags conflict with an existing mark flags. */ - if (fan_flags & FAN_MARK_EVICTABLE && - !(fsn_mark->flags & FSNOTIFY_MARK_FLAG_NO_IREF)) { - ret = -EEXIST; + ret = fanotify_may_update_existing_mark(fsn_mark, fan_flags); + if (ret) goto out; - }
/* * Error events are pre-allocated per group, only if strictly @@ -1559,6 +1570,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask, __kernel_fsid_t __fsid, *fsid = NULL; u32 valid_mask = FANOTIFY_EVENTS | FANOTIFY_EVENT_FLAGS; unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS; + unsigned int mark_cmd = flags & FANOTIFY_MARK_CMD_BITS; bool ignore = flags & FAN_MARK_IGNORED_MASK; unsigned int obj_type, fid_mode; u32 umask = 0; @@ -1588,7 +1600,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask, return -EINVAL; }
- switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) { + switch (mark_cmd) { case FAN_MARK_ADD: case FAN_MARK_REMOVE: if (!mask) @@ -1677,7 +1689,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask, if (mask & FAN_RENAME && !(fid_mode & FAN_REPORT_NAME)) goto fput_and_out;
- if (flags & FAN_MARK_FLUSH) { + if (mark_cmd == FAN_MARK_FLUSH) { ret = 0; if (mark_type == FAN_MARK_MOUNT) fsnotify_clear_vfsmount_marks_by_group(group); @@ -1693,7 +1705,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask, if (ret) goto fput_and_out;
- if (flags & FAN_MARK_ADD) { + if (mark_cmd == FAN_MARK_ADD) { ret = fanotify_events_supported(group, &path, mask, flags); if (ret) goto path_put_and_out; @@ -1731,7 +1743,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask, }
/* create/update an inode mark */ - switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE)) { + switch (mark_cmd) { case FAN_MARK_ADD: if (mark_type == FAN_MARK_MOUNT) ret = fanotify_add_vfsmount_mark(group, mnt, mask, diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h index 4f6cbe6c6e235..c9e185407ebcb 100644 --- a/include/linux/fanotify.h +++ b/include/linux/fanotify.h @@ -61,15 +61,16 @@ extern struct ctl_table fanotify_table[]; /* for sysctl */ #define FANOTIFY_MARK_TYPE_BITS (FAN_MARK_INODE | FAN_MARK_MOUNT | \ FAN_MARK_FILESYSTEM)
+#define FANOTIFY_MARK_CMD_BITS (FAN_MARK_ADD | FAN_MARK_REMOVE | \ + FAN_MARK_FLUSH) + #define FANOTIFY_MARK_FLAGS (FANOTIFY_MARK_TYPE_BITS | \ - FAN_MARK_ADD | \ - FAN_MARK_REMOVE | \ + FANOTIFY_MARK_CMD_BITS | \ FAN_MARK_DONT_FOLLOW | \ FAN_MARK_ONLYDIR | \ FAN_MARK_IGNORED_MASK | \ FAN_MARK_IGNORED_SURV_MODIFY | \ - FAN_MARK_EVICTABLE | \ - FAN_MARK_FLUSH) + FAN_MARK_EVICTABLE)
/* * Events that can be reported with data type FSNOTIFY_EVENT_PATH.