From: Li Zetao lizetao1@huawei.com
commit 594d2a14f2168c09b13b114c3d457aa939403e52 upstream.
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: [<ffffffff819171e1>] __alloc_file+0x21/0x250 [<ffffffff81918061>] alloc_empty_file+0x41/0xf0 [<ffffffff81948cda>] path_openat+0xea/0x3d30 [<ffffffff8194ec89>] do_filp_open+0x1b9/0x290 [<ffffffff8192660e>] do_open_execat+0xce/0x5b0 [<ffffffff81926b17>] open_exec+0x27/0x50 [<ffffffff81a69250>] load_elf_binary+0x510/0x3ed0 [<ffffffff81927759>] bprm_execve+0x599/0x1240 [<ffffffff8192a997>] do_execveat_common.isra.0+0x4c7/0x680 [<ffffffff8192b078>] __x64_sys_execve+0x88/0xb0 [<ffffffff83bbf0a5>] 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 lizetao1@huawei.com Reviewed-by: Alexey Dobriyan adobriyan@gmail.com Signed-off-by: Kees Cook keescook@chromium.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20221024154421.982230-1-lizetao1@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/binfmt_elf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -907,7 +907,7 @@ static int load_elf_binary(struct linux_ 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 */ @@ -1328,6 +1328,7 @@ out: out_free_dentry: kfree(interp_elf_ex); kfree(interp_elf_phdata); +out_free_file: allow_write_access(interpreter); if (interpreter) fput(interpreter);