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Filename Latest commit message Latest commit date
Jann Horn 9b1ca33ebd firmware_loader: Block path traversal
commit f0e5311aa8022107d63c54e2f03684ec097d1394 upstream.

Most firmware names are hardcoded strings, or are constructed from fairly
constrained format strings where the dynamic parts are just some hex
numbers or such.

However, there are a couple codepaths in the kernel where firmware file
names contain string components that are passed through from a device or
semi-privileged userspace; the ones I could find (not counting interfaces
that require root privileges) are:

 - lpfc_sli4_request_firmware_update() seems to construct the firmware
   filename from "ModelName", a string that was previously parsed out of
   some descriptor ("Vital Product Data") in lpfc_fill_vpd()
 - nfp_net_fw_find() seems to construct a firmware filename from a model
   name coming from nfp_hwinfo_lookup(pf->hwinfo, "nffw.partno"), which I
   think parses some descriptor that was read from the device.
   (But this case likely isn't exploitable because the format string looks
   like "netronome/nic_%s", and there shouldn't be any *folders* starting
   with "netronome/nic_". The previous case was different because there,
   the "%s" is *at the start* of the format string.)
 - module_flash_fw_schedule() is reachable from the
   ETHTOOL_MSG_MODULE_FW_FLASH_ACT netlink command, which is marked as
   GENL_UNS_ADMIN_PERM (meaning CAP_NET_ADMIN inside a user namespace is
   enough to pass the privilege check), and takes a userspace-provided
   firmware name.
   (But I think to reach this case, you need to have CAP_NET_ADMIN over a
   network namespace that a special kind of ethernet device is mapped into,
   so I think this is not a viable attack path in practice.)

Fix it by rejecting any firmware names containing ".." path components.

For what it's worth, I went looking and haven't found any USB device
drivers that use the firmware loader dangerously.

Cc: stable@vger.kernel.org
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Fixes: abb139e75c ("firmware: teach the kernel to load firmware files directly from the filesystem")
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20240828-firmware-traversal-v3-1-c76529c63b5f@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-08 16:20:33 +01:00
arch riscv: Fix fp alignment bug in perf_callchain_user() 2024-11-08 16:20:32 +01:00
block block, bfq: don't break merge chain in bfq_split_bfqq() 2024-11-08 16:20:28 +01:00
certs
crypto crypto: aead,cipher - zeroize key buffer after use 2024-11-08 16:20:33 +01:00
Documentation ipmi: docs: don't advertise deprecated sysfs entries 2024-11-08 16:20:29 +01:00
drivers firmware_loader: Block path traversal 2024-11-08 16:20:33 +01:00
fs f2fs: reduce expensive checkpoint trigger frequency 2024-11-08 16:20:32 +01:00
include tcp: check skb is non-NULL in tcp_rto_delta_us() 2024-11-08 16:20:33 +01:00
init init: open /initrd.image with O_LARGEFILE 2024-04-13 12:51:36 +02:00
ipc ipc: replace costly bailout check in sysvipc_find_ipc() 2024-09-04 13:15:02 +02:00
kernel bpf: Fix bpf_strtol and bpf_strtoul helpers for 32bit 2024-11-08 16:20:31 +01:00
lib xz: cleanup CRC32 edits from 2018 2024-11-08 16:20:30 +01:00
LICENSES
mm memcg_write_event_control(): fix a user-triggerable oops 2024-09-04 13:14:50 +02:00
net netfilter: ctnetlink: compile ctnetlink_label_size with CONFIG_NF_CONNTRACK_EVENTS 2024-11-08 16:20:33 +01:00
samples
scripts scripts: kconfig: merge_config: config files: add a trailing newline 2024-11-08 16:20:24 +01:00
security smackfs: Use rcu_assign_pointer() to ensure safe assignment in smk_set_cipso 2024-11-08 16:20:30 +01:00
sound ASoC: tda7419: fix module autoloading 2024-11-08 16:20:25 +01:00
tools perf time-utils: Fix 32-bit nsec parsing 2024-11-08 16:20:31 +01:00
usr
virt KVM: async_pf: Cleanup kvm_setup_async_pf() 2024-05-02 16:18:32 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore Remove *.orig pattern from .gitignore 2024-11-08 16:20:33 +01:00
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile Linux 5.4.284 2024-09-12 11:03:57 +02:00
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