forked from luck/tmp_suning_uos_patched
[PATCH] core-dumping unreadable binaries via PT_INTERP
Proposed patch to fix #5 in http://www.isec.pl/vulnerabilities/isec-0017-binfmt_elf.txt aka http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2004-1073 To reproduce, do * grab poc at the end of advisory. * add line "eph.p_memsz = 4096;" after "eph.p_filesz = 4096;" where first "4096" is something equal to or greater than 4096. * ./poc /usr/bin/sudo && ls -l Here I get with 2.6.20-rc5: -rw------- 1 ad ad 102400 2007-01-15 19:17 core ---s--x--x 2 root root 101820 2007-01-15 19:15 /usr/bin/sudo Check for MAY_READ like binfmt_misc.c does. Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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c20086de93
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@ -682,6 +682,15 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
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retval = PTR_ERR(interpreter);
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if (IS_ERR(interpreter))
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goto out_free_interp;
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/*
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* If the binary is not readable then enforce
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* mm->dumpable = 0 regardless of the interpreter's
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* permissions.
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*/
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if (file_permission(interpreter, MAY_READ) < 0)
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bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
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retval = kernel_read(interpreter, 0, bprm->buf,
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BINPRM_BUF_SIZE);
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if (retval != BINPRM_BUF_SIZE) {
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@ -234,6 +234,14 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm,
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goto error;
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}
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/*
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* If the binary is not readable then enforce
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* mm->dumpable = 0 regardless of the interpreter's
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* permissions.
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*/
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if (file_permission(interpreter, MAY_READ) < 0)
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bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
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retval = kernel_read(interpreter, 0, bprm->buf,
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BINPRM_BUF_SIZE);
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if (retval < 0)
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