From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Wed, 16 Mar 2022 21:29:11 +0000 (-0400)
Subject: Fix: lttng-elf: untrusted entry size divisor
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=a395e0790af821e6cbd2b73ec907447c728cbfff;p=deliverable%2Flttng-tools.git

Fix: lttng-elf: untrusted entry size divisor

1405557 Untrusted divisor
The divisor could be controlled by an attacker, who could cause a division by zero.

In lttng_elf_get_symbol_offset: An unscrutinized value from an untrusted source used as a divisor (CWE-369)

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I029708a0df4f62fe0031e374d50839c26f4f3f4b
---

diff --git a/src/common/lttng-elf.cpp b/src/common/lttng-elf.cpp
index 992410a88..711447203 100644
--- a/src/common/lttng-elf.cpp
+++ b/src/common/lttng-elf.cpp
@@ -824,6 +824,12 @@ int lttng_elf_get_symbol_offset(int fd, char *symbol, uint64_t *offset)
 	}
 
 	/* Get the number of symbol in the table for the iteration. */
+	if (symtab_hdr.sh_entsize == 0) {
+		DBG("Invalid ELF string table entry size.");
+		ret = LTTNG_ERR_ELF_PARSING;
+		goto free_symbol_table_data;
+	}
+
 	sym_count = symtab_hdr.sh_size / symtab_hdr.sh_entsize;
 
 	/* Loop over all symbol. */