From: Heather McIntyre <hsm2@rice.edu>
Date: Tue, 10 Oct 2023 13:42:47 +0000 (+0200)
Subject: libelf: Fix deadlock in __libelf_readall
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=fdf452658f1962fbb781a130969cc74f9f0c56a7;p=thirdparty%2Felfutils.git

libelf: Fix deadlock in __libelf_readall

	* libelf/elf_readall.c (__libelf_readall): Move rwlock_unlock
	before libelf_acquire_all.

Signed-off-by: Heather S. McIntyre <hsm2@rice.edu>
Signed-off-by: Mark Wielaard <mark@klomp.org>
---

diff --git a/libelf/elf_readall.c b/libelf/elf_readall.c
index d0f9a28c..2d62d447 100644
--- a/libelf/elf_readall.c
+++ b/libelf/elf_readall.c
@@ -84,6 +84,7 @@ __libelf_readall (Elf *elf)
 
       /* If this is an archive and we have derived descriptors get the
 	 locks for all of them.  */
+      rwlock_unlock(elf->lock); // lock will be reacquired next line
       libelf_acquire_all (elf);
 
       if (elf->maximum_size == ~((size_t) 0))
@@ -141,10 +142,8 @@ __libelf_readall (Elf *elf)
 	__libelf_seterrno (ELF_E_NOMEM);
 
       /* Free the locks on the children.  */
-      libelf_release_all (elf);
+      libelf_release_all (elf); // lock is released
     }
 
-  rwlock_unlock (elf->lock);
-
   return (char *) elf->map_address;
 }