CVE-2022-49194
Descriptions du CVE
net: bcmgenet: Use stronger register read/writes to assure ordering
In the Linux kernel, the following vulnerability has been resolved: net: bcmgenet: Use stronger register read/writes to assure ordering GCC12 appears to be much smarter about its dependency tracking and is aware that the relaxed variants are just normal loads and stores and this is causing problems like: [ 210.074549] ------------[ cut here ]------------ [ 210.079223] NETDEV WATCHDOG: enabcm6e4ei0 (bcmgenet): transmit queue 1 timed out [ 210.086717] WARNING: CPU: 1 PID: 0 at net/sched/sch_generic.c:529 dev_watchdog+0x234/0x240 [ 210.095044] Modules linked in: genet(E) nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat] [ 210.146561] ACPI CPPC: PCC check channel failed for ss: 0. ret=-110 [ 210.146927] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G E 5.17.0-rc7G12+ #58 [ 210.153226] CPPC Cpufreq:cppc_scale_freq_workfn: failed to read perf counters [ 210.161349] Hardware name: Raspberry Pi Foundation Raspberry Pi 4 Model B/Raspberry Pi 4 Model B, BIOS EDK2-DEV 02/08/2022 [ 210.161353] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 210.161358] pc : dev_watchdog+0x234/0x240 [ 210.161364] lr : dev_watchdog+0x234/0x240 [ 210.161368] sp : ffff8000080a3a40 [ 210.161370] x29: ffff8000080a3a40 x28: ffffcd425af87000 x27: ffff8000080a3b20 [ 210.205150] x26: ffffcd425aa00000 x25: 0000000000000001 x24: ffffcd425af8ec08 [ 210.212321] x23: 0000000000000100 x22: ffffcd425af87000 x21: ffff55b142688000 [ 210.219491] x20: 0000000000000001 x19: ffff55b1426884c8 x18: ffffffffffffffff [ 210.226661] x17: 64656d6974203120 x16: 0000000000000001 x15: 6d736e617274203a [ 210.233831] x14: 2974656e65676d63 x13: ffffcd4259c300d8 x12: ffffcd425b07d5f0 [ 210.241001] x11: 00000000ffffffff x10: ffffcd425b07d5f0 x9 : ffffcd4258bdad9c [ 210.248171] x8 : 00000000ffffdfff x7 : 000000000000003f x6 : 0000000000000000 [ 210.255341] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000001000 [ 210.262511] x2 : 0000000000001000 x1 : 0000000000000005 x0 : 0000000000000044 [ 210.269682] Call trace: [ 210.272133] dev_watchdog+0x234/0x240 [ 210.275811] call_timer_fn+0x3c/0x15c [ 210.279489] __run_timers.part.0+0x288/0x310 [ 210.283777] run_timer_softirq+0x48/0x80 [ 210.287716] __do_softirq+0x128/0x360 [ 210.291392] __irq_exit_rcu+0x138/0x140 [ 210.295243] irq_exit_rcu+0x1c/0x30 [ 210.298745] el1_interrupt+0x38/0x54 [ 210.302334] el1h_64_irq_handler+0x18/0x24 [ 210.306445] el1h_64_irq+0x7c/0x80 [ 210.309857] arch_cpu_idle+0x18/0x2c [ 210.313445] default_idle_call+0x4c/0x140 [ 210.317470] cpuidle_idle_call+0x14c/0x1a0 [ 210.321584] do_idle+0xb0/0x100 [ 210.324737] cpu_startup_entry+0x30/0x8c [ 210.328675] secondary_start_kernel+0xe4/0x110 [ 210.333138] __secondary_switched+0x94/0x98 The assumption when these were relaxed seems to be that device memory would be mapped non reordering, and that other constructs (spinlocks/etc) would provide the barriers to assure that packet data and in memory rings/queues were ordered with respect to device register reads/writes. This itself seems a bit sketchy, but the real problem with GCC12 is that it is moving the actual reads/writes around at will as though they were independent operations when in truth they are not, but the compiler can't know that. When looking at the assembly dumps for many of these routines its possible to see very clean, but not strictly in program order operations occurring as the compiler would be free to do if these weren't actually register reads/write operations. Its possible to suppress the timeout with a liberal bit of dma_mb()'s sprinkled around but the device still seems unable to reliably send/receive data. A better plan is to use the safer readl/writel everywhere. Since this partially reverts an older commit, which notes the use of the relaxed variants for performance reasons. I would suggest that any performance problems ---truncated---Informations du CVE
Faiblesses connexes
| Nom de la faiblesse | Source | |
|---|---|---|
| No informations. |
Métriques
| Métriques | Score | Gravité | CVSS Vecteur | Source |
|---|---|---|---|---|
| V3.1 | 9.8 | CRITICAL |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
More informations
Base: Exploitabilty MetricsThe Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack Vector This metric reflects the context by which vulnerability exploitation is possible. Network The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers). Attack Complexity This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Low Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. None The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack. User Interaction This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component. None The vulnerable system can be exploited without interaction from any user. Base: Scope MetricsThe Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope. Scope Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs. Unchanged An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority. Base: Impact MetricsThe Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve. Confidentiality Impact This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. High There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. High There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. High There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal MetricsThe Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability. Environmental MetricsThese metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability. |
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| V3.1 | 5.5 | MEDIUM |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
More informations
Base: Exploitabilty MetricsThe Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack Vector This metric reflects the context by which vulnerability exploitation is possible. Local The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Attack Complexity This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Low Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. Low The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources. User Interaction This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component. None The vulnerable system can be exploited without interaction from any user. Base: Scope MetricsThe Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope. Scope Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs. Unchanged An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority. Base: Impact MetricsThe Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve. Confidentiality Impact This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. None There is no loss of confidentiality within the impacted component. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. None There is no loss of integrity within the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. High There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal MetricsThe Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability. Environmental MetricsThese metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability. |
nvd@nist.gov |
EPSS
Score EPSS
Percentile EPSS
Products Mentioned
Configuraton 0
Linux>>Linux_kernel >> Version From (including) 4.14 To (excluding) 5.10.110
Linux>>Linux_kernel >> Version From (including) 5.11 To (excluding) 5.15.33
Linux>>Linux_kernel >> Version From (including) 5.16 To (excluding) 5.16.19
Linux>>Linux_kernel >> Version From (including) 5.17 To (excluding) 5.17.2
