From 594d2a14f2168c09b13b114c3d457aa939403e52 Mon Sep 17 00:00:00 2001 From: Li Zetao Date: Mon, 24 Oct 2022 23:44:21 +0800 Subject: [PATCH] fs/binfmt_elf: Fix memory leak in load_elf_binary() There is a memory leak reported by kmemleak: unreferenced object 0xffff88817104ef80 (size 224): comm "xfs_admin", pid 47165, jiffies 4298708825 (age 1333.476s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 60 a8 b3 00 81 88 ff ff a8 10 5a 00 81 88 ff ff `.........Z..... backtrace: [] __alloc_file+0x21/0x250 [] alloc_empty_file+0x41/0xf0 [] path_openat+0xea/0x3d30 [] do_filp_open+0x1b9/0x290 [] do_open_execat+0xce/0x5b0 [] open_exec+0x27/0x50 [] load_elf_binary+0x510/0x3ed0 [] bprm_execve+0x599/0x1240 [] do_execveat_common.isra.0+0x4c7/0x680 [] __x64_sys_execve+0x88/0xb0 [] do_syscall_64+0x35/0x80 If "interp_elf_ex" fails to allocate memory in load_elf_binary(), the program will take the "out_free_ph" error handing path, resulting in "interpreter" file resource is not released. Fix it by adding an error handing path "out_free_file", which will release the file resource when "interp_elf_ex" failed to allocate memory. Fixes: 0693ffebcfe5 ("fs/binfmt_elf.c: allocate less for static executable") Signed-off-by: Li Zetao Reviewed-by: Alexey Dobriyan Signed-off-by: Kees Cook Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20221024154421.982230-1-lizetao1@huawei.com --- fs/binfmt_elf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 63c7ebb..6a11025 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -911,7 +911,7 @@ static int load_elf_binary(struct linux_binprm *bprm) interp_elf_ex = kmalloc(sizeof(*interp_elf_ex), GFP_KERNEL); if (!interp_elf_ex) { retval = -ENOMEM; - goto out_free_ph; + goto out_free_file; } /* Get the exec headers */ @@ -1354,6 +1354,7 @@ out: out_free_dentry: kfree(interp_elf_ex); kfree(interp_elf_phdata); +out_free_file: allow_write_access(interpreter); if (interpreter) fput(interpreter); -- 2.7.4