Messages in this thread | | | From | "Lubashev, Igor" <> | Subject | RE: [RFC PATCH 0/1] security: add SECURE_KEEP_FSUID to preserve fsuid/fsgid across execve | Date | Wed, 3 Jul 2019 00:58:34 +0000 |
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> From: James Morris <jmorris@namei.org> on Friday, June 14, 2019 11:54 PM: > On Sat, 15 Jun 2019, Lubashev, Igor wrote: > > > Unfortunately, perf is using uid==0 and euid==0 as a "capability bits". > > > > > > In tools/perf/util/evsel.c: > > static bool perf_event_can_profile_kernel(void) > > { > > return geteuid() == 0 || perf_event_paranoid() == -1; > > } > > > > In tools/perf/util/symbol.c: > > static bool symbol__read_kptr_restrict(void) > > { > > ... > > value = ((geteuid() != 0) || (getuid() != 0)) ? > > (atoi(line) != 0) : > > (atoi(line) == 2); > > ... > > } > > These are bugs. They should be checking for CAP_SYS_ADMIN.
Thanks for the suggestion.
Actually, the former one should be checking CAP_SYS_ADMIN, while the latter -- CAP_SYSLOG (see lib/vsprintf.c).
Just posted a patch to perf (http://lists.infradead.org/pipermail/linux-arm-kernel/2019-July/664552.html).
Thank you,
- Igor
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