linux/include/uapi
Amir Goldstein 522249f05c fanotify: allow reporting errors on failure to open fd
When working in "fd mode", fanotify_read() needs to open an fd
from a dentry to report event->fd to userspace.

Opening an fd from dentry can fail for several reasons.
For example, when tasks are gone and we try to open their
/proc files or we try to open a WRONLY file like in sysfs
or when trying to open a file that was deleted on the
remote network server.

Add a new flag FAN_REPORT_FD_ERROR for fanotify_init().
For a group with FAN_REPORT_FD_ERROR, we will send the
event with the error instead of the open fd, otherwise
userspace may not get the error at all.

For an overflow event, we report -EBADF to avoid confusing FAN_NOFD
with -EPERM.  Similarly for pidfd open errors we report either -ESRCH
or the open error instead of FAN_NOPIDFD and FAN_EPIDFD.

In any case, userspace will not know which file failed to
open, so add a debug print for further investigation.

Reported-by: Krishna Vivek Vitta <kvitta@microsoft.com>
Link: https://lore.kernel.org/linux-fsdevel/SI2P153MB07182F3424619EDDD1F393EED46D2@SI2P153MB0718.APCP153.PROD.OUTLOOK.COM/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20241003142922.111539-1-amir73il@gmail.com
2024-10-16 17:43:05 +02:00
..
asm-generic net: add SO_DEVMEM_DONTNEED setsockopt to release RX frags 2024-09-11 20:44:32 -07:00
drm Linux 6.11-rc7 2024-09-11 09:18:15 +02:00
linux fanotify: allow reporting errors on failure to open fd 2024-10-16 17:43:05 +02:00
misc Revert "misc: fastrpc: Restrict untrusted app to attach to privileged PD" 2024-08-15 16:59:14 +02:00
mtd
rdma RDMA/nldev: Expose whether RDMA monitoring is supported 2024-09-13 08:29:34 +03:00
regulator
scsi scsi: mpi3mr: Add ioctl support for HDB 2024-06-26 23:30:09 -04:00
sound Merge branch 'for-linus' into for-next 2024-09-10 10:28:00 +02:00
video
xen xen/privcmd: Add new syscall to get gsi from dev 2024-09-25 09:54:55 +02:00
Kbuild