Eric Lee / linux-smarc-t335x-v3.2

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Commit 8454aeef6fea944ced757ff8e761b59eb3ee960f

Authored by Eugene Teo
Committed by Linus Torvalds
1 parent 563d075702
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

[PATCH] Require mmap handler for a.out executables 

Files supported by fs/proc/base.c, i.e.  /proc/<pid>/*, are not capable of
meeting the validity checks in ELF load_elf_*() handling because they have
no mmap handler which is required by ELF.  In order to stop a.out
executables being used as part of an exploit attack against /proc-related
vulnerabilities, we make a.out executables depend on ->mmap() existing.

Signed-off-by: Eugene Teo <eteo@redhat.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Showing 1 changed file with 14 additions and 0 deletions Side-by-side Diff

... ... @@ -278,6 +278,13 @@
278 278 return -ENOEXEC;
279 279 }
280 280  
  281 + /*
  282 + * Requires a mmap handler. This prevents people from using a.out
  283 + * as part of an exploit attack against /proc-related vulnerabilities.
  284 + */
  285 + if (!bprm->file->f_op || !bprm->file->f_op->mmap)
  286 + return -ENOEXEC;
  287 +
281 288 fd_offset = N_TXTOFF(ex);
282 289  
283 290 /* Check initial limits. This avoids letting people circumvent
... ... @@ -475,6 +482,13 @@
475 482 i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
476 483 goto out;
477 484 }
  485 +
  486 + /*
  487 + * Requires a mmap handler. This prevents people from using a.out
  488 + * as part of an exploit attack against /proc-related vulnerabilities.
  489 + */
  490 + if (!file->f_op || !file->f_op->mmap)
  491 + goto out;
478 492  
479 493 if (N_FLAGS(ex))
480 494 goto out;