Previously it was very likely, when multiple contenders for the symlink
appear in parallel, that algorithm would select wrong symlink (i.e. one
with lower-priority).
Now the algorithm is much more defensive and when we detect change in
set of contenders for the symlink we reevaluate the selection. Same
happens when new symlink replaces already existing symlink that points
to different device node.
Let's open the device node to modify with O_PATH, and then adjust it
only after verifying everything is in order. This fixes a race where the
a device appears, disappears and quickly reappers, while we are still
running the rules for the first appearance: when going by path we'd
possibly adjust half of the old and half of the new node. By O_PATH we
can pin the node while we operate on it, thus removing the race.
Previously, we'd do a superficial racey check if the device node changed
undearneath us, and would propagate EEXIST in that case, failing the
rule set. With this change we'll instead gracefully handle this, exactly
like in the pre-existing case when the device node disappeared in the
meantime.
This partially reverts 25de7aa7b9. I don't think the
change was intended there.
The problem I'm trying to solve: for /dev/kvm we get first an ADD uevent, and
then CHANGE whenever something connects or disconnects to the character device.
The rules in 50-default-udev.rules set UID, GID, and MODE on ADD, but not on
CHANGE. When the change event happens, we would reset the ownership and
permissions.
This happens because node_permissions_apply() would (after 25de7aa7b9)
set uid=gid=0 if they weren't set by the rules.
So let's only pass uid/gid/mode to node_permissions_apply() if appropriately
configured. Also let node_permissions_apply() do the skip of uid/gid/mode if
not set, and rename "always_apply" to more closely reflect its meaning.
This fixes bugs introduced by 29448498c7
and d838e14515.
Previously, RUN and SECLABEL keys are stored in udev_list with its unique
flag is false. If the flag is false, then udev_list is just a linked
list and new entries are always added in the last.
So, we should use OrderedHashmap instead of Hashmap.
Fixes#11368.
$ git grep -e 'This program is free software' -l |grep -v LICENSE | \
xargs perl -i -0pe 's/ \* This program.*?for more details.\s*\*\n( \* You should have.*licenses.>.\n)?//gms'
For some reason they were missed previously. All those files seem to
have proper SDPX tags.
This reworks the SELinux and SMACK label fixing calls in a number of
ways:
1. The two separate boolean arguments of these functions are converted
into a flags type LabelFixFlags.
2. The operations are now implemented based on O_PATH. This should
resolve TTOCTTOU races between determining the label for the file
system object and applying it, as it it allows to pin the object
while we are operating on it.
3. When changing a label fails we'll query the label previously set, and
if matches what we want to set anyway we'll suppress the error.
Also, all calls to label_fix() are now (void)ified, when we ignore the
return values.
Fixes: #8566
We don't have plural in the name of any other -util files and this
inconsistency trips me up every time I try to type this file name
from memory. "formats-util" is even hard to pronounce.
Yu Watanabe