linux/include
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
..
acpi
asm-generic move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
clocksource
crypto move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
cxl
drm Short summary of fixes pull: 2024-10-01 08:15:55 +10:00
dt-bindings soc: convert ep93xx to devicetree 2024-09-26 12:00:25 -07:00
keys KEYS: Remove unused declarations 2024-09-20 18:28:26 +03:00
kunit The core clk framework is left largely untouched this time around except for 2024-09-23 15:01:48 -07:00
kvm
linux fanotify: allow reporting errors on failure to open fd 2024-10-16 17:43:05 +02:00
math-emu
media
memory
misc
net mctp: Handle error of rtnl_register_module(). 2024-10-10 15:39:35 +02:00
pcmcia
ras
rdma move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
rv
scsi move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
soc soc: driver updates for 6.12 2024-09-17 10:48:09 +02:00
sound ALSA: hda: fix trigger_tstamp_latched 2024-10-02 12:50:24 +02:00
target move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
trace for-6.12-rc1-tag 2024-10-04 10:05:13 -07:00
uapi fanotify: allow reporting errors on failure to open fd 2024-10-16 17:43:05 +02:00
ufs Many singleton patches - please see the various changelogs for details. 2024-09-21 08:20:50 -07:00
vdso
video
xen xen: sync elfnote.h from xen tree 2024-09-25 14:15:04 +02:00