kernel/linux.git/include/net/netfilter, branch v5.4.292

netfilter: nft_set_hash: unaligned atomic read on struct nft_set_ext

2025-01-09T12:23:35+00:00

[ Upstream commit 542ed8145e6f9392e3d0a86a0e9027d2ffd183e4 ] Access to genmask field in struct nft_set_ext results in unaligned atomic read: [ 72.130109] Unable to handle kernel paging request at virtual address ffff0000c2bb708c [ 72.131036] Mem abort info: [ 72.131213] ESR = 0x0000000096000021 [ 72.131446] EC = 0x25: DABT (current EL), IL = 32 bits [ 72.132209] SET = 0, FnV = 0 [ 72.133216] EA = 0, S1PTW = 0 [ 72.134080] FSC = 0x21: alignment fault [ 72.135593] Data abort info: [ 72.137194] ISV = 0, ISS = 0x00000021, ISS2 = 0x00000000 [ 72.142351] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 72.145989] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 72.150115] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000237d27000 [ 72.154893] [ffff0000c2bb708c] pgd=0000000000000000, p4d=180000023ffff403, pud=180000023f84b403, pmd=180000023f835403, +pte=0068000102bb7707 [ 72.163021] Internal error: Oops: 0000000096000021 [#1] SMP [...] [ 72.170041] CPU: 7 UID: 0 PID: 54 Comm: kworker/7:0 Tainted: G E 6.13.0-rc3+ #2 [ 72.170509] Tainted: [E]=UNSIGNED_MODULE [ 72.170720] Hardware name: QEMU QEMU Virtual Machine, BIOS edk2-stable202302-for-qemu 03/01/2023 [ 72.171192] Workqueue: events_power_efficient nft_rhash_gc [nf_tables] [ 72.171552] pstate: 21400005 (nzCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 72.171915] pc : nft_rhash_gc+0x200/0x2d8 [nf_tables] [ 72.172166] lr : nft_rhash_gc+0x128/0x2d8 [nf_tables] [ 72.172546] sp : ffff800081f2bce0 [ 72.172724] x29: ffff800081f2bd40 x28: ffff0000c2bb708c x27: 0000000000000038 [ 72.173078] x26: ffff0000c6780ef0 x25: ffff0000c643df00 x24: ffff0000c6778f78 [ 72.173431] x23: 000000000000001a x22: ffff0000c4b1f000 x21: ffff0000c6780f78 [ 72.173782] x20: ffff0000c2bb70dc x19: ffff0000c2bb7080 x18: 0000000000000000 [ 72.174135] x17: ffff0000c0a4e1c0 x16: 0000000000003000 x15: 0000ac26d173b978 [ 72.174485] x14: ffffffffffffffff x13: 0000000000000030 x12: ffff0000c6780ef0 [ 72.174841] x11: 0000000000000000 x10: ffff800081f2bcf8 x9 : ffff0000c3000000 [ 72.175193] x8 : 00000000000004be x7 : 0000000000000000 x6 : 0000000000000000 [ 72.175544] x5 : 0000000000000040 x4 : ffff0000c3000010 x3 : 0000000000000000 [ 72.175871] x2 : 0000000000003a98 x1 : ffff0000c2bb708c x0 : 0000000000000004 [ 72.176207] Call trace: [ 72.176316] nft_rhash_gc+0x200/0x2d8 [nf_tables] (P) [ 72.176653] process_one_work+0x178/0x3d0 [ 72.176831] worker_thread+0x200/0x3f0 [ 72.176995] kthread+0xe8/0xf8 [ 72.177130] ret_from_fork+0x10/0x20 [ 72.177289] Code: 54fff984 d503201f d2800080 91003261 (f820303f) [ 72.177557] ---[ end trace 0000000000000000 ]--- Align struct nft_set_ext to word size to address this and documentation it. pahole reports that this increases the size of elements for rhash and pipapo in 8 bytes on x86_64. Fixes: 7ffc7481153b ("netfilter: nft_set_hash: skip duplicated elements pending gc run") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: Replace zero-length array with flexible-array member

2025-01-09T12:23:35+00:00

[ Upstream commit 6daf14140129d30207ed6a0a69851fa6a3636bda ] The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] Lastly, fix checkpatch.pl warning WARNING: __aligned(size) is preferred over __attribute__((aligned(size))) in net/bridge/netfilter/ebtables.c This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Signed-off-by: Pablo Neira Ayuso Stable-dep-of: 542ed8145e6f ("netfilter: nft_set_hash: unaligned atomic read on struct nft_set_ext") Signed-off-by: Sasha Levin

netfilter: nf_tables: use timestamp to check for set element timeout

2024-08-19T03:33:53+00:00

commit 7395dfacfff65e9938ac0889dafa1ab01e987d15 upstream Add a timestamp field at the beginning of the transaction, store it in the nftables per-netns area. Update set backend .insert, .deactivate and sync gc path to use the timestamp, this avoids that an element expires while control plane transaction is still unfinished. .lookup and .update, which are used from packet path, still use the current time to check if the element has expired. And .get path and dump also since this runs lockless under rcu read size lock. Then, there is async gc which also needs to check the current time since it runs asynchronously from a workqueue. [ NB: rbtree GC updates has been excluded because GC is asynchronous. ] Fixes: c3e1b005ed1c ("netfilter: nf_tables: add set element timeout support") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: fully validate NFT_DATA_VALUE on store to data registers

2024-07-05T07:08:27+00:00

[ Upstream commit 7931d32955e09d0a11b1fe0b6aac1bfa061c005c ] register store validation for NFT_DATA_VALUE is conditional, however, the datatype is always either NFT_DATA_VALUE or NFT_DATA_VERDICT. This only requires a new helper function to infer the register type from the set datatype so this conditional check can be removed. Otherwise, pointer to chain object can be leaked through the registers. Fixes: 96518518cc41 ("netfilter: add nftables") Reported-by: Linus Torvalds Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: nf_tables: fix pointer math issue in nft_byteorder_eval()

2024-02-23T07:25:15+00:00

commit c301f0981fdd3fd1ffac6836b423c4d7a8e0eb63 upstream. The problem is in nft_byteorder_eval() where we are iterating through a loop and writing to dst[0], dst[1], dst[2] and so on... On each iteration we are writing 8 bytes. But dst[] is an array of u32 so each element only has space for 4 bytes. That means that every iteration overwrites part of the previous element. I spotted this bug while reviewing commit caf3ef7468f7 ("netfilter: nf_tables: prevent OOB access in nft_byteorder_eval") which is a related issue. I think that the reason we have not detected this bug in testing is that most of time we only write one element. Fixes: ce1e7989d989 ("netfilter: nft_byteorder: provide 64bit le/be conversion") Signed-off-by: Dan Carpenter Signed-off-by: Pablo Neira Ayuso [Ajay: Modified to apply on v5.4.y] Signed-off-by: Ajay Kaher Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: fix table flag updates

2023-11-28T16:50:23+00:00

commit 179d9ba5559a756f4322583388b3213fe4e391b0 upstream. The dormant flag need to be updated from the preparation phase, otherwise, two consecutive requests to dorm a table in the same batch might try to remove the same hooks twice, resulting in the following warning: hook not found, pf 3 num 0 WARNING: CPU: 0 PID: 334 at net/netfilter/core.c:480 __nf_unregister_net_hook+0x1eb/0x610 net/netfilter/core.c:480 Modules linked in: CPU: 0 PID: 334 Comm: kworker/u4:5 Not tainted 5.12.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:__nf_unregister_net_hook+0x1eb/0x610 net/netfilter/core.c:480 This patch is a partial revert of 0ce7cf4127f1 ("netfilter: nftables: update table flags from the commit phase") to restore the previous behaviour. However, there is still another problem: A batch containing a series of dorm-wakeup-dorm table and vice-versa also trigger the warning above since hook unregistration happens from the preparation phase, while hook registration occurs from the commit phase. To fix this problem, this patch adds two internal flags to annotate the original dormant flag status which are __NFT_TABLE_F_WAS_DORMANT and __NFT_TABLE_F_WAS_AWAKEN, to restore it from the abort path. The __NFT_TABLE_F_UPDATE bitmask allows to handle the dormant flag update with one single transaction. Reported-by: syzbot+7ad5cd1615f2d89c6e7e@syzkaller.appspotmail.com Fixes: 0ce7cf4127f1 ("netfilter: nftables: update table flags from the commit phase") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: nftables: update table flags from the commit phase

2023-11-28T16:50:23+00:00

commit 0ce7cf4127f14078ca598ba9700d813178a59409 upstream. Do not update table flags from the preparation phase. Store the flags update into the transaction, then update the flags from the commit phase. Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: fix memleak when more than 255 elements expired

2023-11-28T16:50:23+00:00

commit cf5000a7787cbc10341091d37245a42c119d26c5 upstream. When more than 255 elements expired we're supposed to switch to a new gc container structure. This never happens: u8 type will wrap before reaching the boundary and nft_trans_gc_space() always returns true. This means we recycle the initial gc container structure and lose track of the elements that came before. While at it, don't deref 'gc' after we've passed it to call_rcu. Fixes: 5f68718b34a5 ("netfilter: nf_tables: GC transaction API to avoid race with control plane") Reported-by: Pablo Neira Ayuso Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: defer gc run if previous batch is still pending

2023-11-28T16:50:23+00:00

commit 8e51830e29e12670b4c10df070a4ea4c9593e961 upstream. Don't queue more gc work, else we may queue the same elements multiple times. If an element is flagged as dead, this can mean that either the previous gc request was invalidated/discarded by a transaction or that the previous request is still pending in the system work queue. The latter will happen if the gc interval is set to a very low value, e.g. 1ms, and system work queue is backlogged. The sets refcount is 1 if no previous gc requeusts are queued, so add a helper for this and skip gc run if old requests are pending. Add a helper for this and skip the gc run in this case. Fixes: f6c383b8c31a ("netfilter: nf_tables: adapt set backend to use GC transaction API") Signed-off-by: Florian Westphal Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: remove busy mark and gc batch API

2023-11-28T16:50:22+00:00

commit a2dd0233cbc4d8a0abb5f64487487ffc9265beb5 upstream. Ditch it, it has been replace it by the GC transaction API and it has no clients anymore. Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman