- 20 Oct, 2016 2 commits
-
-
Ben Hutchings authored
-
Linus Torvalds authored
commit 19be0eaf upstream. This is an ancient bug that was actually attempted to be fixed once (badly) by me eleven years ago in commit 4ceb5db9 ("Fix get_user_pages() race for write access") but that was then undone due to problems on s390 by commit f33ea7f4 ("fix get_user_pages bug"). In the meantime, the s390 situation has long been fixed, and we can now fix it by checking the pte_dirty() bit properly (and do it better). The s390 dirty bit was implemented in abf09bed ("s390/mm: implement software dirty bits") which made it into v3.9. Earlier kernels will have to look at the page state itself. Also, the VM has become more scalable, and what used a purely theoretical race back then has become easier to trigger. To fix it, we introduce a new internal FOLL_COW flag to mark the "yes, we already did a COW" rather than play racy games with FOLL_WRITE that is very fundamental, and then use the pte dirty flag to validate that the FOLL_COW flag is still valid. Reported-and-tested-by:
Phil "not Paul" Oester <kernel@linuxace.com> Acked-by:
Hugh Dickins <hughd@google.com> Reviewed-by:
Michal Hocko <mhocko@suse.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Nick Piggin <npiggin@gmail.com> Cc: Greg Thelen <gthelen@google.com> Cc: stable@vger.kernel.org Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> [carnil: backport to 3.16, adjust context] Signed-off-by:
Ben Hutchings <ben@decadent.org.uk>
-
- 22 Aug, 2016 38 commits
-
-
Ben Hutchings authored
-
Bernhard Thaler authored
commit d26e2c9f upstream. This partially reverts commit 1086bbe9 ("netfilter: ensure number of counters is >0 in do_replace()") in net/bridge/netfilter/ebtables.c. Setting rules with ebtables does not work any more with 1086bbe9 place. There is an error message and no rules set in the end. e.g. ~# ebtables -t nat -A POSTROUTING --src 12:34:56:78:9a:bc -j DROP Unable to update the kernel. Two possible causes: 1. Multiple ebtables programs were executing simultaneously. The ebtables userspace tool doesn't by default support multiple ebtables programs running Reverting the ebtables part of 1086bbe9 makes this work again. Signed-off-by:
Bernhard Thaler <bernhard.thaler@wvnet.at> Signed-off-by:
Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by:
-
Dave Jones authored
commit 1086bbe9 upstream. After improving setsockopt() coverage in trinity, I started triggering vmalloc failures pretty reliably from this code path: warn_alloc_failed+0xe9/0x140 __vmalloc_node_range+0x1be/0x270 vzalloc+0x4b/0x50 __do_replace+0x52/0x260 [ip_tables] do_ipt_set_ctl+0x15d/0x1d0 [ip_tables] nf_setsockopt+0x65/0x90 ip_setsockopt+0x61/0xa0 raw_setsockopt+0x16/0x60 sock_common_setsockopt+0x14/0x20 SyS_setsockopt+0x71/0xd0 It turns out we don't validate that the num_counters field in the struct we pass in from userspace is initialized. The same problem also exists in ebtables, arptables, ipv6, and the compat variants. Signed-off-by:
Dave Jones <davej@codemonkey.org.uk> Signed-off-by:
-
Florian Westphal authored
commit d7591f0c upstream. The three variants use same copy&pasted code, condense this into a helper and use that. Make sure info.name is 0-terminated. Signed-off-by:
Florian Westphal <fw@strlen.de> Signed-off-by:
-
Florian Westphal authored
commit 09d96860 upstream. This looks like refactoring, but its also a bug fix. Problem is that the compat path (32bit iptables, 64bit kernel) lacks a few sanity tests that are done in the normal path. For example, we do not check for underflows and the base chain policies. While its possible to also add such checks to the compat path, its more copy&pastry, for instance we cannot reuse check_underflow() helper as e->target_offset differs in the compat case. Other problem is that it makes auditing for validation errors harder; two places need to be checked and kept in sync. At a high level 32 bit compat works like this: 1- initial pass over blob: validate match/entry offsets, bounds checking lookup all matches and targets do bookkeeping wrt. size delta of 32/64bit structures assign match/target.u.kernel pointer (points at kernel implementation, needed to access ->compatsize etc.) 2- allocate memory according to the total bookkeeping size to contain the translated ruleset 3- second pass over original blob: for each entry, copy the 32bit representation to the newly allocated memory. This also does any special match translations (e.g. adjust 32bit to 64bit longs, etc). 4- check if ruleset is free of loops (chase all jumps) 5-first pass over translated blob: call the checkentry function of all matches and targets. The alternative implemented by this patch is to drop steps 3&4 from the compat process, the translation is changed into an intermediate step rather than a full 1:1 translate_table replacement. In the 2nd pass (step #3), change the 64bit ruleset back to a kernel representation, i.e. put() the kernel pointer and restore ->u.user.name . This gets us a 64bit ruleset that is in the format generated by a 64bit iptables userspace -- we can then use translate_table() to get the 'native' sanity checks. This has two drawbacks: 1. we re-validate all the match and target entry structure sizes even though compat translation is supposed to never generate bogus offsets. 2. we put and then re-lookup each match and target. THe upside is that we get all sanity tests and ruleset validations provided by the normal path and can remove some duplicated compat code. iptables-restore time of autogenerated ruleset with 300k chains of form -A CHAIN0001 -m limit --limit 1/s -j CHAIN0002 -A CHAIN0002 -m limit --limit 1/s -j CHAIN0003 shows no noticeable differences in restore times: old: 0m30.796s new: 0m31.521s 64bit: 0m25.674s Signed-off-by:
-
Florian Westphal authored
commit 0188346f upstream. Always returned 0. Signed-off-by:
-
Florian Westphal authored
commit 329a0807 upstream. Signed-off-by:
-
Florian Westphal authored
commit 7d3f843e upstream. Signed-off-by:
-
Florian Westphal authored
commit 8dddd327 upstream. Signed-off-by:
-
Florian Westphal authored
commit 7b7eba0f upstream. Quoting John Stultz: In updating a 32bit arm device from 4.6 to Linus' current HEAD, I noticed I was having some trouble with networking, and realized that /proc/net/ip_tables_names was suddenly empty. Digging through the registration process, it seems we're catching on the: if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 && target_offset + sizeof(struct xt_standard_target) != next_offset) return -EINVAL; Where next_offset seems to be 4 bytes larger then the offset + standard_target struct size. next_offset needs to be aligned via XT_ALIGN (so we can access all members of ip(6)t_entry struct). This problem didn't show up on i686 as it only needs 4-byte alignment for u64, but iptables userspace on other 32bit arches does insert extra padding. Reported-by:
John Stultz <john.stultz@linaro.org> Tested-by:
-
Florian Westphal authored
commit 13631bfc upstream. Validate that all matches (if any) add up to the beginning of the target and that each match covers at least the base structure size. The compat path should be able to safely re-use the function as the structures only differ in alignment; added a BUILD_BUG_ON just in case we have an arch that adds padding as well. Signed-off-by:
-
Florian Westphal authored
commit ce683e5f upstream. We're currently asserting that targetoff + targetsize <= nextoff. Extend it to also check that targetoff is >= sizeof(xt_entry). Since this is generic code, add an argument pointing to the start of the match/target, we can then derive the base structure size from the delta. We also need the e->elems pointer in a followup change to validate matches. Signed-off-by:
-
Florian Westphal authored
commit 7ed2abdd upstream. We have targets and standard targets -- the latter carries a verdict. The ip/ip6tables validation functions will access t->verdict for the standard targets to fetch the jump offset or verdict for chainloop detection, but this happens before the targets get checked/validated. Thus we also need to check for verdict presence here, else t->verdict can point right after a blob. Spotted with UBSAN while testing malformed blobs. Signed-off-by:
-
Florian Westphal authored
commit fc1221b3 upstream. 32bit rulesets have different layout and alignment requirements, so once more integrity checks get added to xt_check_entry_offsets it will reject well-formed 32bit rulesets. Signed-off-by:
-
Florian Westphal authored
commit a08e4e19 upstream. The target size includes the size of the xt_entry_target struct. Signed-off-by:
-
Florian Westphal authored
commit aa412ba2 upstream. Once we add more sanity testing to xt_check_entry_offsets it becomes relvant if we're expecting a 32bit 'config_compat' blob or a normal one. Since we already have a lot of similar-named functions (check_entry, compat_check_entry, find_and_check_entry, etc.) and the current incarnation is short just fold its contents into the callers. Signed-off-by:
-
Florian Westphal authored
commit 7d35812c upstream. Currently arp/ip and ip6tables each implement a short helper to check that the target offset is large enough to hold one xt_entry_target struct and that t->u.target_size fits within the current rule. Unfortunately these checks are not sufficient. To avoid adding new tests to all of ip/ip6/arptables move the current checks into a helper, then extend this helper in followup patches. Signed-off-by:
-
Florian Westphal authored
commit f24e230d upstream. Ben Hawkes says: In the mark_source_chains function (net/ipv4/netfilter/ip_tables.c) it is possible for a user-supplied ipt_entry structure to have a large next_offset field. This field is not bounds checked prior to writing a counter value at the supplied offset. Base chains enforce absolute verdict. User defined chains are supposed to end with an unconditional return, xtables userspace adds them automatically. But if such return is missing we will move to non-existent next rule. Reported-by:
Ben Hawkes <hawkes@google.com> Signed-off-by:
-
Ashutosh Dixit authored
commit 9bf292bf upstream. The MIC VOP driver does two successive reads from user space to read a variable length data structure. Kernel memory corruption can result if the data structure changes between the two reads. This patch disallows the chance of this happening. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=116651 Reported by: Pengfei Wang <wpengfeinudt@gmail.com> Reviewed-by:
Sudeep Dutt <sudeep.dutt@intel.com> Signed-off-by:
Ashutosh Dixit <ashutosh.dixit@intel.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: - Adjust filename, context - goto exit on failure] Signed-off-by:
-
Eric Dumazet authored
commit 75ff39cc upstream. Yue Cao claims that current host rate limiting of challenge ACKS (RFC 5961) could leak enough information to allow a patient attacker to hijack TCP sessions. He will soon provide details in an academic paper. This patch increases the default limit from 100 to 1000, and adds some randomization so that the attacker can no longer hijack sessions without spending a considerable amount of probes. Based on initial analysis and patch from Linus. Note that we also have per socket rate limiting, so it is tempting to remove the host limit in the future. v2: randomize the count of challenge acks per second, not the period. Fixes: 282f23c6 ("tcp: implement RFC 5961 3.2") Reported-by:
Yue Cao <ycao009@ucr.edu> Signed-off-by:
Eric Dumazet <edumazet@google.com> Suggested-by:
Neal Cardwell <ncardwell@google.com> Acked-by:
Yuchung Cheng <ycheng@google.com> Signed-off-by:
David S. Miller <davem@davemloft.net> [bwh: Backported to 3.16: - Adjust context - Use ACCESS_ONCE() instead of {READ,WRITE}_ONCE()] Signed-off-by:
-
Paul Moore authored
commit 43761473 upstream. There is a double fetch problem in audit_log_single_execve_arg() where we first check the execve(2) argumnets for any "bad" characters which would require hex encoding and then re-fetch the arguments for logging in the audit record[1]. Of course this leaves a window of opportunity for an unsavory application to munge with the data. This patch reworks things by only fetching the argument data once[2] into a buffer where it is scanned and logged into the audit records(s). In addition to fixing the double fetch, this patch improves on the original code in a few other ways: better handling of large arguments which require encoding, stricter record length checking, and some performance improvements (completely unverified, but we got rid of some strlen() calls, that's got to be a good thing). As part of the development of this patch, I've also created a basic regression test for the audit-testsuite, the test can be tracked on GitHub at the following link: * https://github.com/linux-audit/audit-testsuite/issues/25 [1] If you pay careful attention, there is actually a triple fetch problem due to a strnlen_user() call at the top of the function. [2] This is a tiny white lie, we do make a call to strnlen_user() prior to fetching the argument data. I don't like it, but due to the way the audit record is structured we really have no choice unless we copy the entire argument at once (which would require a rather wasteful allocation). The good news is that with this patch the kernel no longer relies on this strnlen_user() value for anything beyond recording it in the log, we also update it with a trustworthy value whenever possible. Reported-by:
Pengfei Wang <wpengfeinudt@gmail.com> Signed-off-by:
Paul Moore <paul@paul-moore.com> [bwh: Backported to 3.16: adjust context] Signed-off-by:
-
Martin Schwidefsky authored
commit 532c34b5 upstream. The sclp_ctl_ioctl_sccb function uses two copy_from_user calls to retrieve the sclp request from user space. The first copy_from_user fetches the length of the request which is stored in the first two bytes of the request. The second copy_from_user gets the complete sclp request, but this copies the length field a second time. A malicious user may have changed the length in the meantime. Reported-by:
Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by:
-
Paul Mackerras authored
commit 93d17397 upstream. It turns out that if the guest does a H_CEDE while the CPU is in a transactional state, and the H_CEDE does a nap, and the nap loses the architected state of the CPU (which is is allowed to do), then we lose the checkpointed state of the virtual CPU. In addition, the transactional-memory state recorded in the MSR gets reset back to non-transactional, and when we try to return to the guest, we take a TM bad thing type of program interrupt because we are trying to transition from non-transactional to transactional with a hrfid instruction, which is not permitted. The result of the program interrupt occurring at that point is that the host CPU will hang in an infinite loop with interrupts disabled. Thus this is a denial of service vulnerability in the host which can be triggered by any guest (and depending on the guest kernel, it can potentially triggered by unprivileged userspace in the guest). This vulnerability has been assigned the ID CVE-2016-5412. To fix this, we save the TM state before napping and restore it on exit from the nap, when handling a H_CEDE in real mode. The case where H_CEDE exits to host virtual mode is already OK (as are other hcalls which exit to host virtual mode) because the exit path saves the TM state. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org> [bwh: Backported to 3.16: adjust context] Signed-off-by:
-
Paul Mackerras authored
commit f024ee09 upstream. This moves the transactional memory state save and restore sequences out of the guest entry/exit paths into separate procedures. This is so that these sequences can be used in going into and out of nap in a subsequent patch. The only code changes here are (a) saving and restore LR on the stack, since these new procedures get called with a bl instruction, (b) explicitly saving r1 into the PACA instead of assuming that HSTATE_HOST_R1(r13) is already set, and (c) removing an unnecessary and redundant setting of MSR[TM] that should have been removed by commit 9d4d0bdd9e0a ("KVM: PPC: Book3S HV: Add transactional memory support", 2013-09-24) but wasn't. Signed-off-by:
-
Kangjie Lu authored
commit 4116def2 upstream. The last field "flags" of object "minfo" is not initialized. Copying this object out may leak kernel stack data. Assign 0 to it to avoid leak. Signed-off-by:
Kangjie Lu <kjlu@gatech.edu> Acked-by:
Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by:
-
Kangjie Lu authored
commit 5d2be142 upstream. link_info.str is a char array of size 60. Memory after the NULL byte is not initialized. Sending the whole object out can cause a leak. Signed-off-by:
-
Kangjie Lu authored
commit e4ec8cc8 upstream. The stack object “r1” has a total size of 32 bytes. Its field “event” and “val” both contain 4 bytes padding. These 8 bytes padding bytes are sent to user without being initialized. Signed-off-by:
Takashi Iwai <tiwai@suse.de> Signed-off-by:
-
Kangjie Lu authored
commit 9a47e9cf upstream. The stack object “r1” has a total size of 32 bytes. Its field “event” and “val” both contain 4 bytes padding. These 8 bytes padding bytes are sent to user without being initialized. Signed-off-by:
-
Kangjie Lu authored
commit cec8f96e upstream. The stack object “tread” has a total size of 32 bytes. Its field “event” and “val” both contain 4 bytes padding. These 8 bytes padding bytes are sent to user without being initialized. Signed-off-by:
-
Kangjie Lu authored
commit 681fef83 upstream. The stack object “ci” has a total size of 8 bytes. Its last 3 bytes are padding bytes which are not initialized and leaked to userland via “copy_to_user”. Signed-off-by:
-
Jann Horn authored
commit e54ad7f1 upstream. This prevents stacking filesystems (ecryptfs and overlayfs) from using procfs as lower filesystem. There is too much magic going on inside procfs, and there is no good reason to stack stuff on top of procfs. (For example, procfs does access checks in VFS open handlers, and ecryptfs by design calls open handlers from a kernel thread that doesn't drop privileges or so.) Signed-off-by:
Jann Horn <jannh@google.com> Signed-off-by:
-
Miklos Szeredi authored
commit 69c433ed upstream. Add a simple read-only counter to super_block that indicates how deep this is in the stack of filesystems. Previously ecryptfs was the only stackable filesystem and it explicitly disallowed multiple layers of itself. Overlayfs, however, can be stacked recursively and also may be stacked on top of ecryptfs or vice versa. To limit the kernel stack usage we must limit the depth of the filesystem stack. Initially the limit is set to 2. Signed-off-by:
Miklos Szeredi <mszeredi@suse.cz> [bwh: Backported to 3.16: drop changes to overlayfs] Signed-off-by:
-
Dan Carpenter authored
commit 6217e5ed upstream. I previously added an integer overflow check here but looking at it now, it's still buggy. The bug happens in snd_compr_allocate_buffer(). We multiply ".fragments" and ".fragment_size" and that doesn't overflow but then we save it in an unsigned int so it truncates the high bits away and we allocate a smaller than expected size. Fixes: b35cc822 ('ALSA: compress_core: integer overflow in snd_compr_allocate_buffer()') Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
-
Hugh Dickins authored
commit 7f556567 upstream. The well-spotted fallocate undo fix is good in most cases, but not when fallocate failed on the very first page. index 0 then passes lend -1 to shmem_undo_range(), and that has two bad effects: (a) that it will undo every fallocation throughout the file, unrestricted by the current range; but more importantly (b) it can cause the undo to hang, because lend -1 is treated as truncation, which makes it keep on retrying until every page has gone, but those already fully instantiated will never go away. Big thank you to xfstests generic/269 which demonstrates this. Fixes: b9b4bb26 ("tmpfs: don't undo fallocate past its last page") Signed-off-by:
-
Jeff Mahoney authored
commit f0fe970d upstream. There are legitimate reasons to disallow mmap on certain files, notably in sysfs or procfs. We shouldn't emulate mmap support on file systems that don't offer support natively. CVE-2016-1583 Signed-off-by:
Jeff Mahoney <jeffm@suse.com> [tyhicks: clean up f_op check by using ecryptfs_file_to_lower()] Signed-off-by:
Tyler Hicks <tyhicks@canonical.com> Signed-off-by:
-
Jan Beulich authored
commit 6f2d9d99 upstream. As of Xen 4.7 PV CPUID doesn't expose either of CPUID[1].ECX[7] and CPUID[0x80000007].EDX[7] anymore, causing the driver to fail to load on both Intel and AMD systems. Doing any kind of hardware capability checks in the driver as a prerequisite was wrong anyway: With the hypervisor being in charge, all such checking should be done by it. If ACPI data gets uploaded despite some missing capability, the hypervisor is free to ignore part or all of that data. Ditch the entire check_prereq() function, and do the only valid check (xen_initial_domain()) in the caller in its place. Signed-off-by:
Jan Beulich <jbeulich@suse.com> Signed-off-by:
David Vrabel <david.vrabel@citrix.com> Signed-off-by:
-
Jan Beulich authored
commit 7469be95 upstream. xenbus_dev_request_and_reply() needs to track whether a transaction is open. For XS_TRANSACTION_START messages it calls transaction_start() and for XS_TRANSACTION_END messages it calls transaction_end(). If sending an XS_TRANSACTION_START message fails or responds with an an error, the transaction is not open and transaction_end() must be called. If sending an XS_TRANSACTION_END message fails, the transaction is still open, but if an error response is returned the transaction is closed. Commit 027bd7e8 ("xen/xenbus: Avoid synchronous wait on XenBus stalling shutdown/restart") introduced a regression where failed XS_TRANSACTION_START messages were leaving the transaction open. This can cause problems with suspend (and migration) as all transactions must be closed before suspending. It appears that the problematic change was added accidentally, so just remove it. Signed-off-by:
-
Ursula Braun authored
commit 7831b4ff upstream. A qeth_card contains a napi_struct linked to the net_device during device probing. This struct must be deleted when removing the qeth device, otherwise Panic on oops can occur when qeth devices are repeatedly removed and added. Fixes: a1c3ed4c ("qeth: NAPI support for l2 and l3 discipline") Signed-off-by:
Ursula Braun <ubraun@linux.vnet.ibm.com> Tested-by:
Alexander Klein <ALKL@de.ibm.com> Signed-off-by:
-
