Bug 1226580 (CVE-2021-47607) - VUL-0: CVE-2021-47607: kernel: bpf: Fix kernel address leakage in atomic cmpxchg's r0 aux reg
Summary: VUL-0: CVE-2021-47607: kernel: bpf: Fix kernel address leakage in atomic cmpx...
Status: RESOLVED FIXED
Alias: CVE-2021-47607
Product: SUSE Security Incidents
Classification: Novell Products
Component: Incidents (show other bugs)
Version: unspecified
Hardware: Other Other
: P3 - Medium : Normal
Target Milestone: ---
Assignee: Security Team bot
QA Contact: Security Team bot
URL: https://smash.suse.de/issue/411395/
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-06-20 09:46 UTC by SMASH SMASH
Modified: 2024-07-10 20:30 UTC (History)
2 users (show)

See Also:
Found By: Security Response Team
Services Priority:
Business Priority:
Blocker: ---
Marketing QA Status: ---
IT Deployment: ---

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Description SMASH SMASH 2024-06-20 09:46:33 UTC 
In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix kernel address leakage in atomic cmpxchg's r0 aux reg

The implementation of BPF_CMPXCHG on a high level has the following parameters:

  .-[old-val]                                          .-[new-val]
  BPF_R0 = cmpxchg{32,64}(DST_REG + insn->off, BPF_R0, SRC_REG)
                          `-[mem-loc]          `-[old-val]

Given a BPF insn can only have two registers (dst, src), the R0 is fixed and
used as an auxilliary register for input (old value) as well as output (returning
old value from memory location). While the verifier performs a number of safety
checks, it misses to reject unprivileged programs where R0 contains a pointer as
old value.

Through brute-forcing it takes about ~16sec on my machine to leak a kernel pointer
with BPF_CMPXCHG. The PoC is basically probing for kernel addresses by storing the
guessed address into the map slot as a scalar, and using the map value pointer as
R0 while SRC_REG has a canary value to detect a matching address.

Fix it by checking R0 for pointers, and reject if that's the case for unprivileged
programs.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-47607
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2021/CVE-2021-47607.mbox
https://git.kernel.org/stable/c/f87a6c160ecc8c7b417d25f508d3f076fe346136
https://git.kernel.org/stable/c/a82fe085f344ef20b452cd5f481010ff96b5c4cd
https://www.cve.org/CVERecord?id=CVE-2021-47607
Comment 3 Andrea Mattiazzo 2024-06-24 13:45:19 UTC 
All done, closing.
Comment 9 Maintenance Automation 2024-07-09 16:30:57 UTC 
SUSE-SU-2024:2372-1: An update that solves 249 vulnerabilities, contains three features and has 45 security fixes can now be installed.

Category: security (important)
Bug References: 1156395, 1190336, 1191958, 1193883, 1194826, 1195065, 1195254, 1195341, 1195349, 1195775, 1196746, 1197915, 1198014, 1199295, 1202767, 1202780, 1205205, 1207361, 1217912, 1218148, 1218570, 1218820, 1219224, 1219633, 1219847, 1220368, 1220812, 1220958, 1221086, 1221282, 1221958, 1222015, 1222072, 1222080, 1222241, 1222254, 1222364, 1222893, 1223013, 1223018, 1223265, 1223384, 1223641, 1224020, 1224331, 1224488, 1224497, 1224498, 1224504, 1224520, 1224539, 1224540, 1224552, 1224583, 1224588, 1224602, 1224603, 1224605, 1224612, 1224614, 1224619, 1224661, 1224662, 1224670, 1224671, 1224674, 1224677, 1224679, 1224696, 1224703, 1224712, 1224716, 1224719, 1224735, 1224749, 1224764, 1224765, 1224766, 1224935, 1224946, 1224951, 1225050, 1225098, 1225105, 1225300, 1225389, 1225391, 1225419, 1225426, 1225448, 1225452, 1225467, 1225475, 1225484, 1225487, 1225514, 1225518, 1225535, 1225585, 1225602, 1225611, 1225681, 1225692, 1225698, 1225699, 1225704, 1225714, 1225726, 1225732, 1225737, 1225749, 1225758, 1225759, 1225760, 1225767, 1225770, 1225823, 1225834, 1225840, 1225866, 1225872, 1225894, 1225945, 1226022, 1226131, 1226145, 1226149, 1226155, 1226211, 1226212, 1226226, 1226514, 1226520, 1226537, 1226538, 1226539, 1226550, 1226552, 1226553, 1226554, 1226556, 1226557, 1226558, 1226559, 1226561, 1226562, 1226563, 1226564, 1226566, 1226567, 1226569, 1226572, 1226575, 1226576, 1226577, 1226579, 1226580, 1226581, 1226582, 1226583, 1226585, 1226587, 1226588, 1226593, 1226595, 1226597, 1226601, 1226602, 1226603, 1226607, 1226610, 1226614, 1226616, 1226617, 1226618, 1226619, 1226621, 1226622, 1226624, 1226626, 1226628, 1226629, 1226632, 1226633, 1226634, 1226637, 1226643, 1226644, 1226645, 1226647, 1226650, 1226653, 1226657, 1226658, 1226669, 1226670, 1226672, 1226673, 1226674, 1226675, 1226678, 1226679, 1226683, 1226685, 1226686, 1226690, 1226691, 1226692, 1226693, 1226696, 1226697, 1226698, 1226699, 1226701, 1226702, 1226703, 1226704, 1226705, 1226706, 1226708, 1226709, 1226710, 1226711, 1226712, 1226713, 1226715, 1226716, 1226718, 1226719, 1226720, 1226721, 1226730, 1226732, 1226734, 1226735, 1226737, 1226738, 1226739, 1226740, 1226744, 1226746, 1226747, 1226749, 1226754, 1226762, 1226764, 1226767, 1226768, 1226769, 1226771, 1226774, 1226777, 1226780, 1226781, 1226785, 1226786, 1226789, 1226791, 1226839, 1226840, 1226841, 1226842, 1226848, 1226852, 1226857, 1226861, 1226863, 1226864, 1226867, 1226868, 1226876, 1226878, 1226883, 1226886, 1226890, 1226891, 1226895, 1226908, 1226915, 1226928, 1226948, 1226949, 1226950, 1226953, 1226962, 1226976, 1226992, 1226994, 1226996, 1227066, 1227096, 1227101, 1227103, 1227274
CVE References: CVE-2021-4439, CVE-2021-47089, CVE-2021-47432, CVE-2021-47515, CVE-2021-47534, CVE-2021-47538, CVE-2021-47539, CVE-2021-47555, CVE-2021-47566, CVE-2021-47571, CVE-2021-47572, CVE-2021-47576, CVE-2021-47577, CVE-2021-47578, CVE-2021-47580, CVE-2021-47582, CVE-2021-47583, CVE-2021-47584, CVE-2021-47585, CVE-2021-47586, CVE-2021-47587, CVE-2021-47589, CVE-2021-47592, CVE-2021-47595, CVE-2021-47596, CVE-2021-47597, CVE-2021-47600, CVE-2021-47601, CVE-2021-47602, CVE-2021-47603, CVE-2021-47604, CVE-2021-47605, CVE-2021-47607, CVE-2021-47608, CVE-2021-47609, CVE-2021-47610, CVE-2021-47611, CVE-2021-47612, CVE-2021-47614, CVE-2021-47615, CVE-2021-47616, CVE-2021-47617, CVE-2021-47618, CVE-2021-47619, CVE-2021-47620, CVE-2022-48711, CVE-2022-48712, CVE-2022-48713, CVE-2022-48714, CVE-2022-48715, CVE-2022-48716, CVE-2022-48717, CVE-2022-48718, CVE-2022-48720, CVE-2022-48721, CVE-2022-48722, CVE-2022-48723, CVE-2022-48724, CVE-2022-48725, CVE-2022-48726, CVE-2022-48727, CVE-2022-48728, CVE-2022-48729, CVE-2022-48730, CVE-2022-48732, CVE-2022-48733, CVE-2022-48734, CVE-2022-48735, CVE-2022-48736, CVE-2022-48737, CVE-2022-48738, CVE-2022-48739, CVE-2022-48740, CVE-2022-48743, CVE-2022-48744, CVE-2022-48745, CVE-2022-48746, CVE-2022-48747, CVE-2022-48748, CVE-2022-48749, CVE-2022-48751, CVE-2022-48752, CVE-2022-48753, CVE-2022-48754, CVE-2022-48755, CVE-2022-48756, CVE-2022-48758, CVE-2022-48759, CVE-2022-48760, CVE-2022-48761, CVE-2022-48763, CVE-2022-48765, CVE-2022-48766, CVE-2022-48767, CVE-2022-48768, CVE-2022-48769, CVE-2022-48770, CVE-2022-48771, CVE-2022-48772, CVE-2023-24023, CVE-2023-52622, CVE-2023-52658, CVE-2023-52667, CVE-2023-52670, CVE-2023-52672, CVE-2023-52675, CVE-2023-52735, CVE-2023-52737, CVE-2023-52752, CVE-2023-52766, CVE-2023-52784, CVE-2023-52787, CVE-2023-52800, CVE-2023-52835, CVE-2023-52837, CVE-2023-52843, CVE-2023-52845, CVE-2023-52846, CVE-2023-52869, CVE-2023-52881, CVE-2023-52882, CVE-2023-52884, CVE-2024-26625, CVE-2024-26644, CVE-2024-26720, CVE-2024-26842, CVE-2024-26845, CVE-2024-26923, CVE-2024-26973, CVE-2024-27432, CVE-2024-33619, CVE-2024-35247, CVE-2024-35789, CVE-2024-35790, CVE-2024-35807, CVE-2024-35814, CVE-2024-35835, CVE-2024-35848, CVE-2024-35857, CVE-2024-35861, CVE-2024-35862, CVE-2024-35864, CVE-2024-35869, CVE-2024-35878, CVE-2024-35884, CVE-2024-35886, CVE-2024-35896, CVE-2024-35898, CVE-2024-35900, CVE-2024-35905, CVE-2024-35925, CVE-2024-35950, CVE-2024-35956, CVE-2024-35958, CVE-2024-35960, CVE-2024-35962, CVE-2024-35997, CVE-2024-36005, CVE-2024-36008, CVE-2024-36017, CVE-2024-36020, CVE-2024-36021, CVE-2024-36025, CVE-2024-36477, CVE-2024-36478, CVE-2024-36479, CVE-2024-36890, CVE-2024-36894, CVE-2024-36899, CVE-2024-36900, CVE-2024-36904, CVE-2024-36915, CVE-2024-36916, CVE-2024-36917, CVE-2024-36919, CVE-2024-36934, CVE-2024-36937, CVE-2024-36940, CVE-2024-36945, CVE-2024-36949, CVE-2024-36960, CVE-2024-36964, CVE-2024-36965, CVE-2024-36967, CVE-2024-36969, CVE-2024-36971, CVE-2024-36975, CVE-2024-36978, CVE-2024-37021, CVE-2024-37078, CVE-2024-37354, CVE-2024-38381, CVE-2024-38388, CVE-2024-38390, CVE-2024-38540, CVE-2024-38541, CVE-2024-38544, CVE-2024-38545, CVE-2024-38546, CVE-2024-38547, CVE-2024-38548, CVE-2024-38549, CVE-2024-38550, CVE-2024-38552, CVE-2024-38553, CVE-2024-38555, CVE-2024-38556, CVE-2024-38557, CVE-2024-38559, CVE-2024-38560, CVE-2024-38564, CVE-2024-38565, CVE-2024-38567, CVE-2024-38568, CVE-2024-38571, CVE-2024-38573, CVE-2024-38578, CVE-2024-38579, CVE-2024-38580, CVE-2024-38581, CVE-2024-38582, CVE-2024-38583, CVE-2024-38587, CVE-2024-38590, CVE-2024-38591, CVE-2024-38594, CVE-2024-38597, CVE-2024-38599, CVE-2024-38600, CVE-2024-38601, CVE-2024-38603, CVE-2024-38605, CVE-2024-38608, CVE-2024-38616, CVE-2024-38618, CVE-2024-38619, CVE-2024-38621, CVE-2024-38627, CVE-2024-38630, CVE-2024-38633, CVE-2024-38634, CVE-2024-38635, CVE-2024-38659, CVE-2024-38661, CVE-2024-38780, CVE-2024-39301, CVE-2024-39468, CVE-2024-39469, CVE-2024-39471
Jira References: PED-8491, PED-8570, PED-8690
Maintenance Incident: [SUSE:Maintenance:34676](https://smelt.suse.de/incident/34676/)
Sources used:
Public Cloud Module 15-SP5 (src):
 kernel-source-azure-5.14.21-150500.33.60.1, kernel-syms-azure-5.14.21-150500.33.60.1
openSUSE Leap 15.5 (src):
 kernel-source-azure-5.14.21-150500.33.60.1, kernel-syms-azure-5.14.21-150500.33.60.1

NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.
Comment 10 Maintenance Automation 2024-07-10 20:30:30 UTC 
SUSE-SU-2024:2394-1: An update that solves 249 vulnerabilities, contains three features and has 44 security fixes can now be installed.

Category: security (important)
Bug References: 1156395, 1190336, 1191958, 1193883, 1194826, 1195065, 1195254, 1195341, 1195349, 1195775, 1196746, 1197915, 1198014, 1199295, 1202767, 1202780, 1205205, 1207361, 1217912, 1218148, 1218570, 1218820, 1219224, 1219633, 1219847, 1220368, 1220812, 1220958, 1221086, 1221282, 1221958, 1222015, 1222072, 1222080, 1222241, 1222254, 1222364, 1222893, 1223013, 1223018, 1223265, 1223384, 1223641, 1224020, 1224331, 1224488, 1224497, 1224498, 1224504, 1224520, 1224539, 1224540, 1224552, 1224583, 1224588, 1224602, 1224603, 1224605, 1224612, 1224614, 1224619, 1224661, 1224662, 1224670, 1224671, 1224674, 1224677, 1224679, 1224696, 1224703, 1224712, 1224716, 1224719, 1224735, 1224749, 1224764, 1224765, 1224766, 1224935, 1224946, 1224951, 1225050, 1225098, 1225105, 1225300, 1225389, 1225391, 1225419, 1225426, 1225448, 1225452, 1225467, 1225475, 1225484, 1225487, 1225514, 1225518, 1225535, 1225585, 1225602, 1225611, 1225681, 1225692, 1225698, 1225699, 1225704, 1225714, 1225726, 1225732, 1225737, 1225749, 1225758, 1225759, 1225760, 1225767, 1225770, 1225823, 1225834, 1225840, 1225866, 1225872, 1225894, 1226022, 1226131, 1226145, 1226149, 1226155, 1226211, 1226212, 1226226, 1226514, 1226520, 1226537, 1226538, 1226539, 1226550, 1226552, 1226553, 1226554, 1226556, 1226557, 1226558, 1226559, 1226561, 1226562, 1226563, 1226564, 1226566, 1226567, 1226569, 1226572, 1226575, 1226576, 1226577, 1226579, 1226580, 1226581, 1226582, 1226583, 1226585, 1226587, 1226588, 1226593, 1226595, 1226597, 1226601, 1226602, 1226603, 1226607, 1226610, 1226614, 1226616, 1226617, 1226618, 1226619, 1226621, 1226622, 1226624, 1226626, 1226628, 1226629, 1226632, 1226633, 1226634, 1226637, 1226643, 1226644, 1226645, 1226647, 1226650, 1226653, 1226657, 1226658, 1226669, 1226670, 1226672, 1226673, 1226674, 1226675, 1226678, 1226679, 1226683, 1226685, 1226686, 1226690, 1226691, 1226692, 1226693, 1226696, 1226697, 1226698, 1226699, 1226701, 1226702, 1226703, 1226704, 1226705, 1226706, 1226708, 1226709, 1226710, 1226711, 1226712, 1226713, 1226715, 1226716, 1226718, 1226719, 1226720, 1226721, 1226730, 1226732, 1226734, 1226735, 1226737, 1226738, 1226739, 1226740, 1226744, 1226746, 1226747, 1226749, 1226754, 1226762, 1226764, 1226767, 1226768, 1226769, 1226771, 1226774, 1226777, 1226780, 1226781, 1226785, 1226786, 1226789, 1226791, 1226839, 1226840, 1226841, 1226842, 1226848, 1226852, 1226857, 1226861, 1226863, 1226864, 1226867, 1226868, 1226876, 1226878, 1226883, 1226886, 1226890, 1226891, 1226895, 1226908, 1226915, 1226928, 1226948, 1226949, 1226950, 1226953, 1226962, 1226976, 1226992, 1226994, 1226996, 1227066, 1227096, 1227101, 1227103, 1227274
CVE References: CVE-2021-4439, CVE-2021-47089, CVE-2021-47432, CVE-2021-47515, CVE-2021-47534, CVE-2021-47538, CVE-2021-47539, CVE-2021-47555, CVE-2021-47566, CVE-2021-47571, CVE-2021-47572, CVE-2021-47576, CVE-2021-47577, CVE-2021-47578, CVE-2021-47580, CVE-2021-47582, CVE-2021-47583, CVE-2021-47584, CVE-2021-47585, CVE-2021-47586, CVE-2021-47587, CVE-2021-47589, CVE-2021-47592, CVE-2021-47595, CVE-2021-47596, CVE-2021-47597, CVE-2021-47600, CVE-2021-47601, CVE-2021-47602, CVE-2021-47603, CVE-2021-47604, CVE-2021-47605, CVE-2021-47607, CVE-2021-47608, CVE-2021-47609, CVE-2021-47610, CVE-2021-47611, CVE-2021-47612, CVE-2021-47614, CVE-2021-47615, CVE-2021-47616, CVE-2021-47617, CVE-2021-47618, CVE-2021-47619, CVE-2021-47620, CVE-2022-48711, CVE-2022-48712, CVE-2022-48713, CVE-2022-48714, CVE-2022-48715, CVE-2022-48716, CVE-2022-48717, CVE-2022-48718, CVE-2022-48720, CVE-2022-48721, CVE-2022-48722, CVE-2022-48723, CVE-2022-48724, CVE-2022-48725, CVE-2022-48726, CVE-2022-48727, CVE-2022-48728, CVE-2022-48729, CVE-2022-48730, CVE-2022-48732, CVE-2022-48733, CVE-2022-48734, CVE-2022-48735, CVE-2022-48736, CVE-2022-48737, CVE-2022-48738, CVE-2022-48739, CVE-2022-48740, CVE-2022-48743, CVE-2022-48744, CVE-2022-48745, CVE-2022-48746, CVE-2022-48747, CVE-2022-48748, CVE-2022-48749, CVE-2022-48751, CVE-2022-48752, CVE-2022-48753, CVE-2022-48754, CVE-2022-48755, CVE-2022-48756, CVE-2022-48758, CVE-2022-48759, CVE-2022-48760, CVE-2022-48761, CVE-2022-48763, CVE-2022-48765, CVE-2022-48766, CVE-2022-48767, CVE-2022-48768, CVE-2022-48769, CVE-2022-48770, CVE-2022-48771, CVE-2022-48772, CVE-2023-24023, CVE-2023-52622, CVE-2023-52658, CVE-2023-52667, CVE-2023-52670, CVE-2023-52672, CVE-2023-52675, CVE-2023-52735, CVE-2023-52737, CVE-2023-52752, CVE-2023-52766, CVE-2023-52784, CVE-2023-52787, CVE-2023-52800, CVE-2023-52835, CVE-2023-52837, CVE-2023-52843, CVE-2023-52845, CVE-2023-52846, CVE-2023-52869, CVE-2023-52881, CVE-2023-52882, CVE-2023-52884, CVE-2024-26625, CVE-2024-26644, CVE-2024-26720, CVE-2024-26842, CVE-2024-26845, CVE-2024-26923, CVE-2024-26973, CVE-2024-27432, CVE-2024-33619, CVE-2024-35247, CVE-2024-35789, CVE-2024-35790, CVE-2024-35807, CVE-2024-35814, CVE-2024-35835, CVE-2024-35848, CVE-2024-35857, CVE-2024-35861, CVE-2024-35862, CVE-2024-35864, CVE-2024-35869, CVE-2024-35878, CVE-2024-35884, CVE-2024-35886, CVE-2024-35896, CVE-2024-35898, CVE-2024-35900, CVE-2024-35905, CVE-2024-35925, CVE-2024-35950, CVE-2024-35956, CVE-2024-35958, CVE-2024-35960, CVE-2024-35962, CVE-2024-35997, CVE-2024-36005, CVE-2024-36008, CVE-2024-36017, CVE-2024-36020, CVE-2024-36021, CVE-2024-36025, CVE-2024-36477, CVE-2024-36478, CVE-2024-36479, CVE-2024-36890, CVE-2024-36894, CVE-2024-36899, CVE-2024-36900, CVE-2024-36904, CVE-2024-36915, CVE-2024-36916, CVE-2024-36917, CVE-2024-36919, CVE-2024-36934, CVE-2024-36937, CVE-2024-36940, CVE-2024-36945, CVE-2024-36949, CVE-2024-36960, CVE-2024-36964, CVE-2024-36965, CVE-2024-36967, CVE-2024-36969, CVE-2024-36971, CVE-2024-36975, CVE-2024-36978, CVE-2024-37021, CVE-2024-37078, CVE-2024-37354, CVE-2024-38381, CVE-2024-38388, CVE-2024-38390, CVE-2024-38540, CVE-2024-38541, CVE-2024-38544, CVE-2024-38545, CVE-2024-38546, CVE-2024-38547, CVE-2024-38548, CVE-2024-38549, CVE-2024-38550, CVE-2024-38552, CVE-2024-38553, CVE-2024-38555, CVE-2024-38556, CVE-2024-38557, CVE-2024-38559, CVE-2024-38560, CVE-2024-38564, CVE-2024-38565, CVE-2024-38567, CVE-2024-38568, CVE-2024-38571, CVE-2024-38573, CVE-2024-38578, CVE-2024-38579, CVE-2024-38580, CVE-2024-38581, CVE-2024-38582, CVE-2024-38583, CVE-2024-38587, CVE-2024-38590, CVE-2024-38591, CVE-2024-38594, CVE-2024-38597, CVE-2024-38599, CVE-2024-38600, CVE-2024-38601, CVE-2024-38603, CVE-2024-38605, CVE-2024-38608, CVE-2024-38616, CVE-2024-38618, CVE-2024-38619, CVE-2024-38621, CVE-2024-38627, CVE-2024-38630, CVE-2024-38633, CVE-2024-38634, CVE-2024-38635, CVE-2024-38659, CVE-2024-38661, CVE-2024-38780, CVE-2024-39301, CVE-2024-39468, CVE-2024-39469, CVE-2024-39471
Jira References: PED-8491, PED-8570, PED-8690
Maintenance Incident: [SUSE:Maintenance:34699](https://smelt.suse.de/incident/34699/)
Sources used:
openSUSE Leap 15.5 (src):
 kernel-livepatch-SLE15-SP5-RT_Update_17-1-150500.11.3.1, kernel-syms-rt-5.14.21-150500.13.61.1, kernel-source-rt-5.14.21-150500.13.61.1
SUSE Linux Enterprise Micro 5.5 (src):
 kernel-source-rt-5.14.21-150500.13.61.1
SUSE Linux Enterprise Live Patching 15-SP5 (src):
 kernel-livepatch-SLE15-SP5-RT_Update_17-1-150500.11.3.1
SUSE Real Time Module 15-SP5 (src):
 kernel-syms-rt-5.14.21-150500.13.61.1, kernel-source-rt-5.14.21-150500.13.61.1

NOTE: This line indicates an update has been released for the listed product(s). At times this might be only a partial fix. If you have questions please reach out to maintenance coordination.