CVSS: 5.5EPSS: 0%CPEs: 5EXPL: 0CVE-2021-46921 – locking/qrwlock: Fix ordering in queued_write_lock_slowpath()
https://notcve.org/view.php?id=CVE-2021-46921
In the Linux kernel, the following vulnerability has been resolved: locking/qrwlock: Fix ordering in queued_write_lock_slowpath() While this code is executed with the wait_lock held, a reader can acquire the lock without holding wait_lock. The writer side loops checking the value with the atomic_cond_read_acquire(), but only truly acquires the lock when the compare-and-exchange is completed successfully which isn’t ordered. This exposes the window between the acquire and the cmpxchg to an A-B-A problem which allows reads following the lock acquisition to observe values speculatively before the write lock is truly acquired. We've seen a problem in epoll where the reader does a xchg while holding the read lock, but the writer can see a value change out from under it. Writer | Reader -------------------------------------------------------------------------------- ep_scan_ready_list() | |- write_lock_irq() | |- queued_write_lock_slowpath() | |- atomic_cond_read_acquire() | | read_lock_irqsave(&ep->lock, flags); --> (observes value before unlock) | chain_epi_lockless() | | epi->next = xchg(&ep->ovflist, epi); | | read_unlock_irqrestore(&ep->lock, flags); | | | atomic_cmpxchg_relaxed() | |-- READ_ONCE(ep->ovflist); | A core can order the read of the ovflist ahead of the atomic_cmpxchg_relaxed(). Switching the cmpxchg to use acquire semantics addresses this issue at which point the atomic_cond_read can be switched to use relaxed semantics. [peterz: use try_cmpxchg()] En el kernel de Linux, se resolvió la siguiente vulnerabilidad: lock/qrwlock: corrige el orden en queued_write_lock_slowpath() Mientras este código se ejecuta con wait_lock retenido, un lector puede adquirir el bloqueo sin mantener wait_lock. El lado del escritor realiza un bucle para verificar el valor con atomic_cond_read_acquire(), pero solo adquiere realmente el bloqueo cuando la comparación e intercambio se completa con éxito, lo cual no está ordenado. • https://git.kernel.org/stable/c/b519b56e378ee82caf9b079b04f5db87dedc3251 https://git.kernel.org/stable/c/5902f9453a313be8fe78cbd7e7ca9dba9319fc6e https://git.kernel.org/stable/c/82808cc026811fbc3ecf0c0b267a12a339eead56 https://git.kernel.org/stable/c/82fa9ced35d88581cffa4a1c856fc41fca96d80a https://git.kernel.org/stable/c/d558fcdb17139728347bccc60a16af3e639649d2 https://git.kernel.org/stable/c/84a24bf8c52e66b7ac89ada5e3cfbe72d65c1896 • CWE-668: Exposure of Resource to Wrong Sphere •
CVSS: 5.5EPSS: 0%CPEs: 3EXPL: 0CVE-2021-46920 – dmaengine: idxd: Fix clobbering of SWERR overflow bit on writeback
https://notcve.org/view.php?id=CVE-2021-46920
In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: Fix clobbering of SWERR overflow bit on writeback Current code blindly writes over the SWERR and the OVERFLOW bits. Write back the bits actually read instead so the driver avoids clobbering the OVERFLOW bit that comes after the register is read. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: dmaengine: idxd: corrige el problema del bit de desbordamiento SWERR en la reescritura El código actual escribe ciegamente sobre los bits SWERR y OVERFLOW. En su lugar, vuelva a escribir los bits realmente leídos para que el controlador evite dañar el bit OVERFLOW que viene después de leer el registro. • https://git.kernel.org/stable/c/bfe1d56091c1a404b3d4ce7e9809d745fc4453bb https://git.kernel.org/stable/c/a5ad12d5d69c63af289a37f05187a0c6fe93553d https://git.kernel.org/stable/c/02981a44a0e402089775416371bd2e0c935685f8 https://git.kernel.org/stable/c/ea941ac294d75d0ace50797aebf0056f6f8f7a7f •
CVSS: 5.5EPSS: 0%CPEs: 3EXPL: 0CVE-2021-46919 – dmaengine: idxd: fix wq size store permission state
https://notcve.org/view.php?id=CVE-2021-46919
In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: fix wq size store permission state WQ size can only be changed when the device is disabled. Current code allows change when device is enabled but wq is disabled. Change the check to detect device state. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: dmaengine: idxd: corregir el tamaño de wq estado del permiso de almacenamiento El tamaño de WQ solo se puede cambiar cuando el dispositivo está deshabilitado. El código actual permite cambios cuando el dispositivo está habilitado pero wq está deshabilitado. • https://git.kernel.org/stable/c/c52ca478233c172b2d322b5241d6279a8661cbba https://git.kernel.org/stable/c/4ecf25595273203010bc8318c4aee60ad64037ae https://git.kernel.org/stable/c/05b7791c4c4aa8304368fdc55ae911f6b34e7281 https://git.kernel.org/stable/c/0fff71c5a311e1264988179f7dcc217fda15fadd •
CVSS: 5.5EPSS: 0%CPEs: 4EXPL: 0CVE-2021-46917 – dmaengine: idxd: fix wq cleanup of WQCFG registers
https://notcve.org/view.php?id=CVE-2021-46917
In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: fix wq cleanup of WQCFG registers A pre-release silicon erratum workaround where wq reset does not clear WQCFG registers was leaked into upstream code. Use wq reset command instead of blasting the MMIO region. This also address an issue where we clobber registers in future devices. En el kernel de Linux, se resolvió la siguiente vulnerabilidad: dmaengine: idxd: corrige la limpieza de wq de los registros WQCFG. Se filtró en el código ascendente un workaround de errata de silicio de prelanzamiento en la que el restablecimiento de wq no borra los registros WQCFG. • https://git.kernel.org/stable/c/da32b28c95a79e399e18c03f8178f41aec9c66e4 https://git.kernel.org/stable/c/2a2df2bd10de44c3804661ed15157817c12d6291 https://git.kernel.org/stable/c/e5eb9757fe4c2392e069246ae78badc573af1833 https://git.kernel.org/stable/c/f7dc8f5619165e1fa3383d0c2519f502d9e2a1a9 https://git.kernel.org/stable/c/ea9aadc06a9f10ad20a90edc0a484f1147d88a7a • CWE-668: Exposure of Resource to Wrong Sphere •
CVSS: 5.5EPSS: 0%CPEs: 6EXPL: 0CVE-2021-46915 – netfilter: nft_limit: avoid possible divide error in nft_limit_init
https://notcve.org/view.php?id=CVE-2021-46915
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_limit: avoid possible divide error in nft_limit_init div_u64() divides u64 by u32. nft_limit_init() wants to divide u64 by u64, use the appropriate math function (div64_u64) divide error: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8390 Comm: syz-executor188 Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:div_u64_rem include/linux/math64.h:28 [inline] RIP: 0010:div_u64 include/linux/math64.h:127 [inline] RIP: 0010:nft_limit_init+0x2a2/0x5e0 net/netfilter/nft_limit.c:85 Code: ef 4c 01 eb 41 0f 92 c7 48 89 de e8 38 a5 22 fa 4d 85 ff 0f 85 97 02 00 00 e8 ea 9e 22 fa 4c 0f af f3 45 89 ed 31 d2 4c 89 f0 <49> f7 f5 49 89 c6 e8 d3 9e 22 fa 48 8d 7d 48 48 b8 00 00 00 00 00 RSP: 0018:ffffc90009447198 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000200000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff875152e6 RDI: 0000000000000003 RBP: ffff888020f80908 R08: 0000200000000000 R09: 0000000000000000 R10: ffffffff875152d8 R11: 0000000000000000 R12: ffffc90009447270 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 000000000097a300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200001c4 CR3: 0000000026a52000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: nf_tables_newexpr net/netfilter/nf_tables_api.c:2675 [inline] nft_expr_init+0x145/0x2d0 net/netfilter/nf_tables_api.c:2713 nft_set_elem_expr_alloc+0x27/0x280 net/netfilter/nf_tables_api.c:5160 nf_tables_newset+0x1997/0x3150 net/netfilter/nf_tables_api.c:4321 nfnetlink_rcv_batch+0x85a/0x21b0 net/netfilter/nfnetlink.c:456 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:580 [inline] nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:598 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:674 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae En el kernel de Linux se ha resuelto la siguiente vulnerabilidad: netfilter: nft_limit: evita posible error de división en nft_limit_init div_u64() divide u64 entre u32. nft_limit_init() quiere dividir u64 entre u64, use la función matemática apropiada (div64_u64) error de división: 0000 [#1] CPU PREEMPT SMP KASAN: 1 PID: 8390 Comm: syz-executor188 Not tainted 5.12.0-rc4-syzkaller # 0 Nombre del hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:div_u64_rem include/linux/math64.h:28 [en línea] RIP: 0010:div_u64 include/linux/math64.h: 127 [en línea] RIP: 0010:nft_limit_init+0x2a2/0x5e0 net/netfilter/nft_limit.c:85 Código: ef 4c 01 eb 41 0f 92 c7 48 89 de e8 38 a5 22 fa 4d 85 ff 0f 85 97 02 00 00 e8 ea 9e 22 fa 4c 0f af f3 45 89 ed 31 d2 4c 89 f0 <49> f7 f5 49 89 c6 e8 d3 9e 22 fa 48 8d 7d 48 48 b8 00 00 00 00 00 RSP: 0018:ffffc90009447198 EF LAGS: 00010246 RAX: 0000000000000000 RBX: 0000200000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff875152e6 RDI: 0000000000000003 RBP: ffff888 020f80908 R08: 0000200000000000 R09: 0000000000000000 R10: ffffffff875152d8 R11: 0000000000000000 R12: ffffc90009447270 R13: 000000000000 0000 R14: 0000000000000000 R15: 0000000000000000 FS: 000000000097a300(0000) GS :ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200001c4 CR3: 0000000026a52000 CR 4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 00000000000000000 DR6: 00000000ffe0ff0 DR7: 00000 00000000400 Rastreo de llamadas: nf_tables_newexpr net/netfilter/nf_tables_api.c:2675 [en línea] nft_expr_init+0x145/0x2d0 net/netfilter/nf_tables_api.c:2713 nft_set_elem_expr_alloc+0x27/0x280 net/netfilter/nf_tables_api.c:5160 nf_tables_newset+0x1997/0x3150 net/netfilter/ nf_tables_api.c:4321 nfnetlink_rcv_batch+0x85a/0x21b0 net/netfilter/nfnetlink.c:456 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:580 [en línea] nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:59 8 netlink_unicast_kernel red/netlink /af_netlink.c:1312 [en línea] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:654 [en línea] sock_sendmsg+ 0xcf/0x120 net/socket.c:674 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433 do_sys llamada_64+0x2d/ 0x70 arch/x86/entry/common.c:46 entrada_SYSCALL_64_after_hwframe+0x44/0xae A denial of service flaw was found in nft_limit_init in netfilter's nft_limit in the Linux Kernel. This issue occurs due to an inappropriate math function selection, which may cause an availability threat. • https://git.kernel.org/stable/c/c26844eda9d4fdbd266660e3b3de2d0270e3a1ed https://git.kernel.org/stable/c/9065ccb9ec92c5120e7e97958397ebdb454f23d6 https://git.kernel.org/stable/c/fadd3c4afdf3d4c21f4d138502f8b76334987e26 https://git.kernel.org/stable/c/01fb1626b620cb37a65ad08e0f626489e8f042ef https://git.kernel.org/stable/c/dc1732baa9da5b68621586bf8636ebbc27dc62d2 https://git.kernel.org/stable/c/1bb3ee4259936cc3b2d80a4a480bbb4868575071 https://git.kernel.org/stable/c/b895bdf5d643b6feb7c60856326dd4feb6981560 https://access.redhat.com/security/cve/CVE-2021-46915 • CWE-369: Divide By Zero •