user/sven/linux.git/drivers, branch v4.9.259

dm era: Update in-core bitset after committing the metadata

2021-03-03T16:44:46Z

commit 2099b145d77c1d53f5711f029c37cc537897cee6 upstream. In case of a system crash, dm-era might fail to mark blocks as written in its metadata, although the corresponding writes to these blocks were passed down to the origin device and completed successfully. Consider the following sequence of events: 1. We write to a block that has not been yet written in the current era 2. era_map() checks the in-core bitmap for the current era and sees that the block is not marked as written. 3. The write is deferred for submission after the metadata have been updated and committed. 4. The worker thread processes the deferred write (process_deferred_bios()) and marks the block as written in the in-core bitmap, **before** committing the metadata. 5. The worker thread starts committing the metadata. 6. We do more writes that map to the same block as the write of step (1) 7. era_map() checks the in-core bitmap and sees that the block is marked as written, **although the metadata have not been committed yet**. 8. These writes are passed down to the origin device immediately and the device reports them as completed. 9. The system crashes, e.g., power failure, before the commit from step (5) finishes. When the system recovers and we query the dm-era target for the list of written blocks it doesn't report the aforementioned block as written, although the writes of step (6) completed successfully. The issue is that era_map() decides whether to defer or not a write based on non committed information. The root cause of the bug is that we update the in-core bitmap, **before** committing the metadata. Fix this by updating the in-core bitmap **after** successfully committing the metadata. Fixes: eec40579d84873 ("dm: add era target") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Nikos Tsironis Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

net: icmp: pass zeroed opts from icmp{,v6}_ndo_send before sending

2021-03-03T16:44:46Z

commit ee576c47db60432c37e54b1e2b43a8ca6d3a8dca upstream. The icmp{,v6}_send functions make all sorts of use of skb->cb, casting it with IPCB or IP6CB, assuming the skb to have come directly from the inet layer. But when the packet comes from the ndo layer, especially when forwarded, there's no telling what might be in skb->cb at that point. As a result, the icmp sending code risks reading bogus memory contents, which can result in nasty stack overflows such as this one reported by a user: panic+0x108/0x2ea __stack_chk_fail+0x14/0x20 __icmp_send+0x5bd/0x5c0 icmp_ndo_send+0x148/0x160 In icmp_send, skb->cb is cast with IPCB and an ip_options struct is read from it. The optlen parameter there is of particular note, as it can induce writes beyond bounds. There are quite a few ways that can happen in __ip_options_echo. For example: // sptr/skb are attacker-controlled skb bytes sptr = skb_network_header(skb); // dptr/dopt points to stack memory allocated by __icmp_send dptr = dopt->__data; // sopt is the corrupt skb->cb in question if (sopt->rr) { optlen = sptr[sopt->rr+1]; // corrupt skb->cb + skb->data soffset = sptr[sopt->rr+2]; // corrupt skb->cb + skb->data // this now writes potentially attacker-controlled data, over // flowing the stack: memcpy(dptr, sptr+sopt->rr, optlen); } In the icmpv6_send case, the story is similar, but not as dire, as only IP6CB(skb)->iif and IP6CB(skb)->dsthao are used. The dsthao case is worse than the iif case, but it is passed to ipv6_find_tlv, which does a bit of bounds checking on the value. This is easy to simulate by doing a `memset(skb->cb, 0x41, sizeof(skb->cb));` before calling icmp{,v6}_ndo_send, and it's only by good fortune and the rarity of icmp sending from that context that we've avoided reports like this until now. For example, in KASAN: BUG: KASAN: stack-out-of-bounds in __ip_options_echo+0xa0e/0x12b0 Write of size 38 at addr ffff888006f1f80e by task ping/89 CPU: 2 PID: 89 Comm: ping Not tainted 5.10.0-rc7-debug+ #5 Call Trace: dump_stack+0x9a/0xcc print_address_description.constprop.0+0x1a/0x160 __kasan_report.cold+0x20/0x38 kasan_report+0x32/0x40 check_memory_region+0x145/0x1a0 memcpy+0x39/0x60 __ip_options_echo+0xa0e/0x12b0 __icmp_send+0x744/0x1700 Actually, out of the 4 drivers that do this, only gtp zeroed the cb for the v4 case, while the rest did not. So this commit actually removes the gtp-specific zeroing, while putting the code where it belongs in the shared infrastructure of icmp{,v6}_ndo_send. This commit fixes the issue by passing an empty IPCB or IP6CB along to the functions that actually do the work. For the icmp_send, this was already trivial, thanks to __icmp_send providing the plumbing function. For icmpv6_send, this required a tiny bit of refactoring to make it behave like the v4 case, after which it was straight forward. Fixes: a2b78e9b2cac ("sunvnet: generate ICMP PTMUD messages for smaller port MTUs") Reported-by: SinYu Reviewed-by: Willem de Bruijn Link: https://lore.kernel.org/netdev/CAF=yD-LOF116aHub6RMe8vB8ZpnrrnoTdqhobEx+bvoA8AsP0w@mail.gmail.com/T/ Signed-off-by: Jason A. Donenfeld Link: https://lore.kernel.org/r/20210223131858.72082-1-Jason@zx2c4.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

sunvnet: use icmp_ndo_send helper

2021-03-03T16:44:46Z

commit 67c9a7e1e3ac491b5df018803639addc36f154ba upstream. Because sunvnet is calling icmp from network device context, it should use the ndo helper so that the rate limiting applies correctly. While we're at it, doing the additional route lookup before calling icmp_ndo_send is superfluous, since this is the job of the icmp code in the first place. Signed-off-by: Jason A. Donenfeld Cc: Shannon Nelson Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

gtp: use icmp_ndo_send helper

2021-03-03T16:44:46Z

commit e0fce6f945a26d4e953a147fe7ca11410322c9fe upstream. Because gtp is calling icmp from network device context, it should use the ndo helper so that the rate limiting applies correctly. Signed-off-by: Jason A. Donenfeld Cc: Harald Welte Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

dm era: only resize metadata in preresume

2021-03-03T16:44:45Z

commit cca2c6aebe86f68103a8615074b3578e854b5016 upstream. Metadata resize shouldn't happen in the ctr. The ctr loads a temporary (inactive) table that will only become active upon resume. That is why resize should always be done in terms of resume. Otherwise a load (ctr) whose inactive table never becomes active will incorrectly resize the metadata. Also, perform the resize directly in preresume, instead of using the worker to do it. The worker might run other metadata operations, e.g., it could start digestion, before resizing the metadata. These operations will end up using the old size. This could lead to errors, like: device-mapper: era: metadata_digest_transcribe_writeset: dm_array_set_value failed device-mapper: era: process_old_eras: digest step failed, stopping digestion The reason of the above error is that the worker started the digestion of the archived writeset using the old, larger size. As a result, metadata_digest_transcribe_writeset tried to write beyond the end of the era array. Fixes: eec40579d84873 ("dm: add era target") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Nikos Tsironis Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm era: Reinitialize bitset cache before digesting a new writeset

2021-03-03T16:44:45Z

commit 2524933307fd0036d5c32357c693c021ab09a0b0 upstream. In case of devices with at most 64 blocks, the digestion of consecutive eras uses the writeset of the first era as the writeset of all eras to digest, leading to lost writes. That is, we lose the information about what blocks were written during the affected eras. The digestion code uses a dm_disk_bitset object to access the archived writesets. This structure includes a one word (64-bit) cache to reduce the number of array lookups. This structure is initialized only once, in metadata_digest_start(), when we kick off digestion. But, when we insert a new writeset into the writeset tree, before the digestion of the previous writeset is done, or equivalently when there are multiple writesets in the writeset tree to digest, then all these writesets are digested using the same cache and the cache is not re-initialized when moving from one writeset to the next. For devices with more than 64 blocks, i.e., the size of the cache, the cache is indirectly invalidated when we move to a next set of blocks, so we avoid the bug. But for devices with at most 64 blocks we end up using the same cached data for digesting all archived writesets, i.e., the cache is loaded when digesting the first writeset and it never gets reloaded, until the digestion is done. As a result, the writeset of the first era to digest is used as the writeset of all the following archived eras, leading to lost writes. Fix this by reinitializing the dm_disk_bitset structure, and thus invalidating the cache, every time the digestion code starts digesting a new writeset. Fixes: eec40579d84873 ("dm: add era target") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Nikos Tsironis Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm era: Use correct value size in equality function of writeset tree

2021-03-03T16:44:45Z

commit 64f2d15afe7b336aafebdcd14cc835ecf856df4b upstream. Fix the writeset tree equality test function to use the right value size when comparing two btree values. Fixes: eec40579d84873 ("dm: add era target") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Nikos Tsironis Reviewed-by: Ming-Hung Tsai Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm era: Fix bitset memory leaks

2021-03-03T16:44:45Z

commit 904e6b266619c2da5c58b5dce14ae30629e39645 upstream. Deallocate the memory allocated for the in-core bitsets when destroying the target and in error paths. Fixes: eec40579d84873 ("dm: add era target") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Nikos Tsironis Reviewed-by: Ming-Hung Tsai Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm era: Verify the data block size hasn't changed

2021-03-03T16:44:45Z

commit c8e846ff93d5eaa5384f6f325a1687ac5921aade upstream. dm-era doesn't support changing the data block size of existing devices, so check explicitly that the requested block size for a new target matches the one stored in the metadata. Fixes: eec40579d84873 ("dm: add era target") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Nikos Tsironis Reviewed-by: Ming-Hung Tsai Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm era: Recover committed writeset after crash

2021-03-03T16:44:44Z

commit de89afc1e40fdfa5f8b666e5d07c43d21a1d3be0 upstream. Following a system crash, dm-era fails to recover the committed writeset for the current era, leading to lost writes. That is, we lose the information about what blocks were written during the affected era. dm-era assumes that the writeset of the current era is archived when the device is suspended. So, when resuming the device, it just moves on to the next era, ignoring the committed writeset. This assumption holds when the device is properly shut down. But, when the system crashes, the code that suspends the target never runs, so the writeset for the current era is not archived. There are three issues that cause the committed writeset to get lost: 1. dm-era doesn't load the committed writeset when opening the metadata 2. The code that resizes the metadata wipes the information about the committed writeset (assuming it was loaded at step 1) 3. era_preresume() starts a new era, without taking into account that the current era might not have been archived, due to a system crash. To fix this: 1. Load the committed writeset when opening the metadata 2. Fix the code that resizes the metadata to make sure it doesn't wipe the loaded writeset 3. Fix era_preresume() to check for a loaded writeset and archive it, before starting a new era. Fixes: eec40579d84873 ("dm: add era target") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Nikos Tsironis Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman