37 lines
933 B
C
37 lines
933 B
C
#define _GNU_SOURCE
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#include <unistd.h>
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#include <signal.h>
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#include "syscall.h"
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#include "libc.h"
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struct ctx {
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size_t count;
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const gid_t *list;
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int ret;
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};
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static void do_setgroups(void *p)
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{
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struct ctx *c = p;
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if (c->ret<0) return;
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int ret = __syscall(SYS_setgroups, c->count, c->list);
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if (ret && !c->ret) {
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/* If one thread fails to set groups after another has already
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* succeeded, forcibly killing the process is the only safe
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* thing to do. State is inconsistent and dangerous. Use
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* SIGKILL because it is uncatchable. */
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__block_all_sigs(0);
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__syscall(SYS_kill, __syscall(SYS_getpid), SIGKILL);
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}
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c->ret = ret;
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}
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int setgroups(size_t count, const gid_t list[])
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{
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/* ret is initially nonzero so that failure of the first thread does not
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* trigger the safety kill above. */
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struct ctx c = { .count = count, .list = list, .ret = 1 };
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__synccall(do_setgroups, &c);
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return __syscall_ret(c.ret);
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}
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