kernel/include/net/ax25.h, branch linux-5.2.y

ax25: fix possible use-after-free

2019-01-23T19:18:00Z

syzbot found that ax25 routes where not properly protected against concurrent use [1]. In this particular report the bug happened while copying ax25->digipeat. Fix this problem by making sure we call ax25_get_route() while ax25_route_lock is held, so that no modification could happen while using the route. The current two ax25_get_route() callers do not sleep, so this change should be fine. Once we do that, ax25_get_route() no longer needs to grab a reference on the found route. [1] ax25_connect(): syz-executor0 uses autobind, please contact jreuter@yaina.de BUG: KASAN: use-after-free in memcpy include/linux/string.h:352 [inline] BUG: KASAN: use-after-free in kmemdup+0x42/0x60 mm/util.c:113 Read of size 66 at addr ffff888066641a80 by task syz-executor2/531 ax25_connect(): syz-executor0 uses autobind, please contact jreuter@yaina.de CPU: 1 PID: 531 Comm: syz-executor2 Not tainted 5.0.0-rc2+ #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1db/0x2d0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x123/0x190 mm/kasan/generic.c:191 memcpy+0x24/0x50 mm/kasan/common.c:130 memcpy include/linux/string.h:352 [inline] kmemdup+0x42/0x60 mm/util.c:113 kmemdup include/linux/string.h:425 [inline] ax25_rt_autobind+0x25d/0x750 net/ax25/ax25_route.c:424 ax25_connect.cold+0x30/0xa4 net/ax25/af_ax25.c:1224 __sys_connect+0x357/0x490 net/socket.c:1664 __do_sys_connect net/socket.c:1675 [inline] __se_sys_connect net/socket.c:1672 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1672 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458099 Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f870ee22c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099 RDX: 0000000000000048 RSI: 0000000020000080 RDI: 0000000000000005 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 ax25_connect(): syz-executor4 uses autobind, please contact jreuter@yaina.de R10: 0000000000000000 R11: 0000000000000246 R12: 00007f870ee236d4 R13: 00000000004be48e R14: 00000000004ce9a8 R15: 00000000ffffffff Allocated by task 526: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504 ax25_connect(): syz-executor5 uses autobind, please contact jreuter@yaina.de kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609 kmalloc include/linux/slab.h:545 [inline] ax25_rt_add net/ax25/ax25_route.c:95 [inline] ax25_rt_ioctl+0x3b9/0x1270 net/ax25/ax25_route.c:233 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe ax25_connect(): syz-executor5 uses autobind, please contact jreuter@yaina.de Freed by task 550: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kfree+0xcf/0x230 mm/slab.c:3806 ax25_rt_add net/ax25/ax25_route.c:92 [inline] ax25_rt_ioctl+0x304/0x1270 net/ax25/ax25_route.c:233 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763 sock_do_ioctl+0xe2/0x400 net/socket.c:950 sock_ioctl+0x32f/0x6c0 net/socket.c:1074 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888066641a80 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [ffff888066641a80, ffff888066641ae0) The buggy address belongs to the page: page:ffffea0001999040 count:1 mapcount:0 mapping:ffff88812c3f04c0 index:0x0 flags: 0x1fffc0000000200(slab) ax25_connect(): syz-executor4 uses autobind, please contact jreuter@yaina.de raw: 01fffc0000000200 ffffea0001817948 ffffea0002341dc8 ffff88812c3f04c0 raw: 0000000000000000 ffff888066641000 0000000100000020 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888066641980: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888066641a00: 00 00 00 00 00 00 00 00 02 fc fc fc fc fc fc fc >ffff888066641a80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888066641b00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888066641b80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc Signed-off-by: Eric Dumazet Cc: Ralf Baechle Reported-by: syzbot Signed-off-by: David S. Miller

proc: introduce proc_create_seq{,_data}

2018-05-16T05:23:35Z

Variants of proc_create{,_data} that directly take a struct seq_operations argument and drastically reduces the boilerplate code in the callers. All trivial callers converted over. Signed-off-by: Christoph Hellwig

net: Make ax25_ptr depend on CONFIG_AX25

2018-02-14T16:55:33Z

Signed-off-by: David Ahern Signed-off-by: David S. Miller

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

net, ax25: convert ax25_cb.refcount from atomic_t to refcount_t

2017-07-04T21:35:19Z

refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: David S. Miller

net, ax25: convert ax25_route.refcount from atomic_t to refcount_t

2017-07-04T21:35:19Z

net, ax25: convert ax25_uid_assoc.refcount from atomic_t to refcount_t

2017-07-04T21:35:19Z

ax25: Stop using sock->sk_protinfo.

2015-06-28T23:55:44Z

Just make a ax25_sock structure that provides the ax25_cb pointer. Signed-off-by: David S. Miller

ax25: Stop using magic neighbour cache operations.

2015-03-03T19:44:41Z

Before the ax25 stack calls dev_queue_xmit it always calls ax25_type_trans which sets skb->protocol to ETH_P_AX25. Which means that by looking at the protocol type it is possible to detect IP packets that have not been munged by the ax25 stack in ndo_start_xmit and call a function to munge them. Rename ax25_neigh_xmit to ax25_ip_xmit and tweak the return type and value to be appropriate for an ndo_start_xmit function. Update all of the ax25 devices to test the protocol type for ETH_P_IP and return ax25_ip_xmit as the first thing they do. This preserves the existing semantics of IP packet processing, but the timing will be a little different as the IP packets now pass through the qdisc layer before reaching the ax25 ip packet processing. Remove the now unnecessary ax25 neighbour table operations. Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller

ax25: Refactor to use private neighbour operations.

2015-03-02T21:43:40Z

AX25 already has it's own private arp cache operations to isolate it's abuse of dev_rebuild_header to transmit packets. Add a function ax25_neigh_construct that will allow all of the ax25 devices to force using these operations, so that the generic arp code does not need to. Cc: Ralf Baechle Cc: linux-hams@vger.kernel.org Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller