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Re: [PATCH v2 4/4] sideband: add options to allow more control sequences to be passed through

From
Patrick Steinhardt <ps@pks.im>
Date
Jan 19, 2026, 07:20 UTC
Message-ID
<aW3bSYCIPMhJT1mf@pks.im>
In-Reply-To
<xmqq3445bn33.fsf@gitster.g>
On Fri, Jan 16, 2026 at 07:21:04AM -0800, Junio C Hamano wrote:
Show 34 quoted lines
> Ondrej Pohorelsky <opohorel@redhat.com> writes:
> 
> > Hi, I just want to weight in from the downstream maintainer POV.
> > We've been carrying the patches Johannes has created in Fedora, CentOS
> > and RHEL for at least half a year now.
> > The only change I did is to make the new behavior opt-in by default
> > and give the RHEL customers a release note explaining it.
> 
> Thanks for your great input.  FWIW, I do not think anybody around
> here is against "opt-in with a note" approach at all.
> 
> > I think the patches proposed are making sense, and they should be
> > merged. Even having them as opt-in is better than not having them
> > merged at all.
> 
> I do not think anybody disagrees with this sentiment.  Back when the
> patches originally was discussed on the public list here, nobody was
> against adding it as an _optional_ feature to filter some byte
> sequences out of the end-user's data stream, and the review comments
> that led to the topic marked to be "expecting a reroll", if I recall
> correctly, were all about "why would we make this on by default?"
> Peff's message that reignited the topic this time around is also
> about the same.
> 
> We are still hearing from Dscho that he cannot think of a scenario
> where making this mandatory with opt-out would break existing
> legitimate setup people may have (I am paraphrasing [*]), but I
> think that is aiming in the wrong direction.  It does not matter if
> you consider the approach your users take is "broken by design"; as
> long as it works for them in their (limited) settings, it is a valid
> arrangement to send arbitrary byte sequence over the sideband even
> it happens to include ANSI escapes and other "curiosities".  We have
> in no position to unilaterally break them, telling them that we left
> a way open for them to disable.  That is not how to deliver features.

I think what I strongly disagree with is that this is considered to be a feature. I myself don't consider this to be a feature though, but rather a security fix for a bug that can lead to arbitrary code execution on the client-side, for example via title bar injection.

It's not the first time that we change existing behaviour in a backwards incompatible way because of a newly discovered attack vector. So I have to wonder what's so different about this particular case here.

Patrick
Previous: Junio C HamanoNext: brian m. carlson
Message 42 of 86 in “Sanitize sideband channel messages”
  1. 0/3 Sanitize sideband channel messagesJohannes Schindelin via GitGitGadget, Jan 14, 2025
  2. 1/3 sideband: mask control charactersJohannes Schindelin via GitGitGadget, Jan 14, 2025
  3. Phillip WoodJan 15, 2025
  4. Johannes SchindelinDec 2, 2025
  5. Andreas SchwabJan 15, 2025
  6. Junio C HamanoJan 15, 2025
  7. 2/3 sideband: introduce an "escape hatch" to allow control charactersJohannes Schindelin via GitGitGadget, Jan 14, 2025
  8. 3/3 sideband: do allow ANSI color sequences by defaultJohannes Schindelin via GitGitGadget, Jan 14, 2025
  9. brian m. carlsonJan 14, 2025
  10. Junio C HamanoJan 16, 2025
  11. Ondrej PohorelskyJan 28, 2025
  12. Junio C HamanoJan 31, 2025
  13. Johannes SchindelinDec 2, 2025
  14. brian m. carlsonDec 3, 2025
  15. Johannes SchindelinDec 3, 2025
  16. Phillip WoodJan 15, 2025
  17. Johannes SchindelinDec 2, 2025
  18. 0/4 Sanitize sideband channel messagesJohannes Schindelin via GitGitGadget, Dec 17, 2025
  19. 1/4 sideband: mask control charactersJohannes Schindelin via GitGitGadget, Dec 17, 2025
  20. Patrick SteinhardtJan 9, 2026
  21. Johannes SchindelinJan 16, 2026
  22. 2/4 sideband: introduce an "escape hatch" to allow control charactersJohannes Schindelin via GitGitGadget, Dec 17, 2025
  23. Junio C HamanoDec 18, 2025
  24. Johannes SchindelinDec 18, 2025
  25. Junio C HamanoDec 19, 2025
  26. Johannes SchindelinJan 16, 2026
  27. Patrick SteinhardtJan 9, 2026
  28. 3/4 sideband: do allow ANSI color sequences by defaultJohannes Schindelin via GitGitGadget, Dec 17, 2025
  29. Patrick SteinhardtJan 9, 2026
  30. Johannes SchindelinJan 16, 2026
  31. 4/4 sideband: add options to allow more control sequences to be passed throughJohannes Schindelin via GitGitGadget, Dec 17, 2025
  32. Patrick SteinhardtJan 9, 2026
  33. brian m. carlsonJan 10, 2026
  34. Jeff KingJan 15, 2026
  35. Junio C HamanoJan 15, 2026
  36. Johannes SchindelinJan 15, 2026
  37. Patrick SteinhardtJan 16, 2026
  38. Ondrej PohorelskyJan 16, 2026
  39. Junio C HamanoJan 16, 2026
  40. Johannes SchindelinJan 16, 2026
  41. Junio C HamanoJan 16, 2026
  42. Patrick SteinhardtJan 19, 2026
  43. brian m. carlsonJan 19, 2026
  44. D. Ben KnobleJan 20, 2026
  45. Junio C HamanoJan 20, 2026
  46. Jeff KingJan 20, 2026
  47. Junio C HamanoJan 20, 2026
  48. Patrick SteinhardtJan 21, 2026
  49. Johannes SchindelinJan 22, 2026
  50. Junio C HamanoJan 22, 2026
  51. brian m. carlsonJan 15, 2026
  52. Junio C HamanoFeb 3, 2026
  53. Johannes SchindelinFeb 3, 2026
  54. Junio C HamanoFeb 3, 2026
  55. Junio C HamanoFeb 4, 2026
  56. Johannes SchindelinJan 16, 2026
  57. 0/5 Sanitize sideband channel messagesJohannes Schindelin via GitGitGadget, Jan 16, 2026
  58. 1/5 sideband: mask control charactersJohannes Schindelin via GitGitGadget, Jan 16, 2026
  59. 2/5 sideband: introduce an "escape hatch" to allow control charactersJohannes Schindelin via GitGitGadget, Jan 16, 2026
  60. 3/5 sideband: do allow ANSI color sequences by defaultJohannes Schindelin via GitGitGadget, Jan 16, 2026
  61. 4/5 sideband: add options to allow more control sequences to be passed throughJohannes Schindelin via GitGitGadget, Jan 16, 2026
  62. 5/5 sideband: offer to configure sanitizing on a per-URL basisJohannes Schindelin via GitGitGadget, Jan 16, 2026
  63. Johannes SchindelinJan 16, 2026
  64. 0/6 Sanitize sideband channel messagesJohannes Schindelin via GitGitGadget, Feb 3, 2026
  65. 1/6 sideband: mask control charactersJohannes Schindelin via GitGitGadget, Feb 3, 2026
  66. 2/6 sideband: introduce an "escape hatch" to allow control charactersJohannes Schindelin via GitGitGadget, Feb 3, 2026
  67. 3/6 sideband: do allow ANSI color sequences by defaultJohannes Schindelin via GitGitGadget, Feb 3, 2026
  68. 4/6 sideband: add options to allow more control sequences to be passed throughJohannes Schindelin via GitGitGadget, Feb 3, 2026
  69. 5/6 sideband: offer to configure sanitizing on a per-URL basisJohannes Schindelin via GitGitGadget, Feb 3, 2026
  70. 6/6 sideband: delay sanitizing by default to Git v3.0Johannes Schindelin via GitGitGadget, Feb 3, 2026
  71. Junio C HamanoFeb 4, 2026
  72. Junio C HamanoFeb 5, 2026
  73. Junio C HamanoFeb 13, 2026
  74. 0/3 Sanitizing sideband outputJunio C Hamano, Mar 2, 2026
  75. 1/3 sideband: drop 'default' configurationJunio C Hamano, Mar 2, 2026
  76. 2/3 sideband: delay sanitizing by default to Git v3.0Junio C Hamano, Mar 2, 2026
  77. 3/3 sideband: conditional documentation fixJunio C Hamano, Mar 2, 2026
  78. 0/7 Sanitizing sideband outputJunio C Hamano, Mar 5, 2026
  79. 1/7 sideband: mask control charactersJunio C Hamano, Mar 5, 2026
  80. 2/7 sideband: introduce an "escape hatch" to allow control charactersJunio C Hamano, Mar 5, 2026
  81. 3/7 sideband: do allow ANSI color sequences by defaultJunio C Hamano, Mar 5, 2026
  82. 4/7 sideband: add options to allow more control sequences to be passed throughJunio C Hamano, Mar 5, 2026
  83. 5/7 sideband: offer to configure sanitizing on a per-URL basisJunio C Hamano, Mar 5, 2026
  84. 6/7 sideband: drop 'default' configurationJunio C Hamano, Mar 5, 2026
  85. 7/7 sideband: delay sanitizing by default to Git v3.0Junio C Hamano, Mar 5, 2026
  86. Shipping 2.55 with stricter "neuter sideband" topicJunio C Hamano, Jun 11, 2026

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