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| author | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2015-02-01 14:33:10 -0500 |
|---|---|---|
| committer | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2015-02-01 17:22:32 -0500 |
| commit | 51ddf61540976fc7b09ce5ace707b27f3acc3871 (patch) | |
| tree | a9d404cb974572c5e52554c09186993d4d56719b /src/shared/util.h | |
| parent | 615938651d3a4fd9253b08da00db22d451a8cef8 (diff) | |
Fix dropping of all capabilities
From fd.o bug 88898:
systemd-resolved fails to start:
Failed to drop capabilities: Operation not permitted
Broken in f11943c53ec181829a821c6b27acf828bab71caa.
Drop all capabilities:
1. prctl(PR_SET_KEEPCAPS, keep_capabilities != 0) // 0 when we drop all
capabilities
2. setresuid() // bye bye capabilities
3. Add CAP_SETPCAP // fails because we have no capabilities
4. Reduce capability bounding set
5. Drop capabilities
6. prctl(PR_SET_KEEPCAPS, 0)
Capabilites should always be kept after setresuid() so that the capability
bounding set can be reduced.
Based-on-a-patch-by: mustrumr97@gmail.com
https://bugs.freedesktop.org/show_bug.cgi?id=88898
We must be careful not to leave PR_SET_KEEPCAPS on. We could use the
setresuid() call to drop capabilities, but the rules when capabilities
are dropped are fairly complex, since a transition to non-zero uid must
happen. Let's instead keep the capabilities during setresuid(), and drop
them later.
Diffstat (limited to 'src/shared/util.h')
0 files changed, 0 insertions, 0 deletions