qemu/hw/9pfs
Vitaly Chikunov e64e27d5cb 9pfs: Fix segfault in do_readdir_many caused by struct dirent overread
`struct dirent' returned from readdir(3) could be shorter (or longer)
than `sizeof(struct dirent)', thus memcpy of sizeof length will overread
into unallocated page causing SIGSEGV. Example stack trace:

 #0  0x00005555559ebeed v9fs_co_readdir_many (/usr/bin/qemu-system-x86_64 + 0x497eed)
 #1  0x00005555559ec2e9 v9fs_readdir (/usr/bin/qemu-system-x86_64 + 0x4982e9)
 #2  0x0000555555eb7983 coroutine_trampoline (/usr/bin/qemu-system-x86_64 + 0x963983)
 #3  0x00007ffff73e0be0 n/a (n/a + 0x0)

While fixing this, provide a helper for any future `struct dirent' cloning.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/841
Cc: qemu-stable@nongnu.org
Co-authored-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Tested-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Acked-by: Greg Kurz <groug@kaod.org>
Tested-by: Vitaly Chikunov <vt@altlinux.org>
Message-Id: <20220216181821.3481527-1-vt@altlinux.org>
[C.S. - Fix typo in source comment. ]
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2022-02-17 16:57:58 +01:00
..
9p-local.c 9pfs: add link to 9p developer docs 2021-07-05 13:03:16 +02:00
9p-local.h
9p-posix-acl.c 9pfs: add link to 9p developer docs 2021-07-05 13:03:16 +02:00
9p-proxy.c 9pfs: add link to 9p developer docs 2021-07-05 13:03:16 +02:00
9p-proxy.h
9p-synth.c 9pfs: Fix segfault in do_readdir_many caused by struct dirent overread 2022-02-17 16:57:58 +01:00
9p-synth.h 9pfs: Fix segfault in do_readdir_many caused by struct dirent overread 2022-02-17 16:57:58 +01:00
9p-util.c 9pfs: add link to 9p developer docs 2021-07-05 13:03:16 +02:00
9p-util.h
9p-xattr-user.c 9pfs: add link to 9p developer docs 2021-07-05 13:03:16 +02:00
9p-xattr.c 9pfs: add link to 9p developer docs 2021-07-05 13:03:16 +02:00
9p-xattr.h
9p.c 9pfs: use P9Array in v9fs_walk() 2021-10-27 14:45:22 +02:00
9p.h 9pfs: drop root_qid 2021-07-05 13:03:16 +02:00
codir.c 9pfs: Fix segfault in do_readdir_many caused by struct dirent overread 2022-02-17 16:57:58 +01:00
cofile.c 9pfs: add link to 9p developer docs 2021-07-05 13:03:16 +02:00
cofs.c 9pfs: add link to 9p developer docs 2021-07-05 13:03:16 +02:00
coth.c 9pfs: add link to 9p developer docs 2021-07-05 13:03:16 +02:00
coth.h 9pfs: fix crash in v9fs_walk() 2021-09-02 13:26:22 +02:00
coxattr.c 9pfs: add link to 9p developer docs 2021-07-05 13:03:16 +02:00
Kconfig hw/9pfs: Fix Kconfig dependency problem between 9pfs and Xen 2020-11-05 15:21:11 +01:00
meson.build hw/9pfs: Fix Kconfig dependency problem between 9pfs and Xen 2020-11-05 15:21:11 +01:00
trace-events docs: fix references to docs/devel/tracing.rst 2021-06-02 06:51:09 +02:00
trace.h
virtio-9p-device.c 9pfs: add link to 9p developer docs 2021-07-05 13:03:16 +02:00
virtio-9p.h
xen-9p-backend.c 9pfs: add link to 9p developer docs 2021-07-05 13:03:16 +02:00
xen-9pfs.h