From: Paul Burton paul.burton@imgtec.com
[ Upstream commit 351b0940d473146923711bc943fc881354a4c1f3 ]
If we hit an error whilst processing a reloc then we would return early from apply_relocate & potentially not free entries in r_mips_hi16_list, thereby leaking memory. Fix this by ensuring that we always run the code to free r_mipps_hi16_list when errors occur.
Signed-off-by: Paul Burton paul.burton@imgtec.com Fixes: 861667dc82f5 ("MIPS: Fix race condition in module relocation code.") Fixes: 04211a574641 ("MIPS: Bail on unsupported module relocs") Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15831/ Signed-off-by: Ralf Baechle ralf@linux-mips.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- arch/mips/kernel/module.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c index 94627a3a6a0d..ddcfb59593b6 100644 --- a/arch/mips/kernel/module.c +++ b/arch/mips/kernel/module.c @@ -251,7 +251,7 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab, u32 *location; unsigned int i, type; Elf_Addr v; - int res; + int err = 0;
pr_debug("Applying relocate section %u to %u\n", relsec, sechdrs[relsec].sh_info); @@ -270,7 +270,8 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab, continue; pr_warn("%s: Unknown symbol %s\n", me->name, strtab + sym->st_name); - return -ENOENT; + err = -ENOENT; + goto out; }
type = ELF_MIPS_R_TYPE(rel[i]); @@ -283,29 +284,32 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab, if (!handler) { pr_err("%s: Unknown relocation type %u\n", me->name, type); - return -EINVAL; + err = -EINVAL; + goto out; }
v = sym->st_value; - res = handler(me, location, v); - if (res) - return res; + err = handler(me, location, v); + if (err) + goto out; }
+out: /* - * Normally the hi16 list should be deallocated at this point. A + * Normally the hi16 list should be deallocated at this point. A * malformed binary however could contain a series of R_MIPS_HI16 - * relocations not followed by a R_MIPS_LO16 relocation. In that - * case, free up the list and return an error. + * relocations not followed by a R_MIPS_LO16 relocation, or if we hit + * an error processing a reloc we might have gotten here before + * reaching the R_MIPS_LO16. In either case, free up the list and + * return an error. */ if (me->arch.r_mips_hi16_list) { free_relocation_chain(me->arch.r_mips_hi16_list); me->arch.r_mips_hi16_list = NULL; - - return -ENOEXEC; + err = err ?: -ENOEXEC; }
- return 0; + return err; }
/* Given an address, look for it in the module exception tables. */